My understanding is that those super duty 455 heads even flowed better than the Chrysler Hemi. These cars were easily the fastest of their day. Thank you for the attention you gave to this historical car!
popular hotrodding December 1972 issue mentions that the SD heads flow better than the hemi heads. Air Flow Research helped to design the heads. I'm sure you heard of them.
Jeff Wilson I also saw something on a video about the SD head's feeling better than the Hemi. I tried to find it on RUclips but couldn't. It is out there somewhere...
I owned a73’ Tran Am ( Brewster green / tan interior) and I wish I never gave it up. I took that car pass 160 on speed and still had more. Thank goodness for great handling. You all have a great day.
@@maximumcoverage5591 Dude...that is real. My father had a 1974 just the normal 455 (no SD) and my older brother , with me in the passenger seat, took it 165 and he let up cause were starting to get spooked. It would have gone faster. You ever been in a vintage T/A?
@@saltydog4759 yup and had a 455 in an Olds cutlass SX as well. I ain't believing it until I see it with a cop radar. I'm not saying the gage didn't read 160, and those things mostly had highway gears unless you special ordered something higher. I've been 160 for sure on motorcycles more than several times, my buddy in high school had a formula 400, no way would that thing hit 160, maybe 120, maybe. Been that fast in a Porsche 911 Turbo and that was smooth as F, both as a passenger and driving it. Been riding in some old cars that looked over 130 on the speedo, every time that needle would sure have some bounce to it. So the chance that they all or even many could go 160. I have a hard time believing that bro. It's really fast. What year was your Dad's and was it automatic or stick?? That must have been the shit to grow up riding in. Lol my one grandmother was a mustang fan, she had a 73 riveria wa 455 and that thing was solid at like 110-120, after a rebuild with more compression and my grandpa putting hollowed out cats on the exhaust. Some bikers were messing with my grandma one day on the highway. So she started going faster until the speedo was buried in her 429 equipped Ford wagon. She said they couldn't hang at 120 and one slowed down to fast and ate it in the median and the other guy she crowded enough so he backed off her. She told my grandpa that she wanted that kind of power in every car she drove. She had 4 kids and a dog and all thier crap in the wagon at the time. What I'm saying is the difference between 120-130 and 160 is a lot, and saying the majority of 455 TA could do 160 is unrealistic bro.
@@maximumcoverage5591 I asked my older brother who was driving that day and he told it me was 143 MPH or so. Just under 145 So, since he was driving that day so many years ago, I'll defer to his memory! Although he did say he let up, but felt it had more in it when he did. I guess I stand corrected. I was only 16 at the time so maybe the number grew in my head over the decades!
Top speed back then had much less to do with Horsepower, and everything to do with gearing. '73 T/A with Firestone "wide 60 ovals" were 25.9" tall, the Automatics had 3.08 rear ends, the 4 Spd 3.42 Redline was 5700 RPM. At 5700 RPM an Automatic car would be 143mph and a 4 spd car would top out at 128! Would they Rev past 5700?, sure but could you Rev it to the required 7300 RPM to get 165 mph in a 4 Spd car? NO WAY! Cars back then were not built for top speed.
I had a 1973 Formula Firebird that was beautiful, but had the 'smoggy' 400 in it. I pulled the weak 400, took a 455 from a Grand Safari wagon, pulled the internals, replaced with a forged crank and rods, '4-brow' pistons, and the AMAZING '46' head stamp heads form a 1968 Pontiac 428 Police Interceptor...along with a 'purple stick' 428 OEM cam. Machinist that did the block work for me said he calculated 10.7:1 compression. Engine dyno'd 571-hp, 602-torque with a 1070-holley on a dual plane Edelbrock intake...and just like that, it went into my 73 Formula...and off to the track we went. The car turned 10.7's pretty consistently at 132-mph, give or take (depending on the weather and temps), with a shift-kitted 400-Turbo automatic. Why does this matter? Because Pontiac COULD HAVE EASILY built this engine in 1970 for the Trans Ams...and didn't...because GM MANDATED that no subdivision of GM could make a car that OUT-PERFORMED the LS6 Corvettes...that's why!
@@jeremythompson9895 You're absolutely correct, sir. The Chevelle was the sole vehicle (except it's half-twin the El Camino) to get the 450hp LS-6 in '70, and in '71 the compression was reduced (along with the power output). The fact is, there were never any "mandates" keeping the corvette on top of the performance hill at GM. Its light weight and large engine bay did that.
I still miss mine. Ordered it brand new before I graduated engineering and didn't have to make a payment until September. All the banks in Blacksburg had to see was your employment offer letter with a start date. It was not an SD, and I was very disappointed when it arrived as my '66 GTO would run rings around it. With a bit of wrenching it was soon going 12 second @ 120s quarter miles. Alas in 1978 life took priority and I had to sell it. Thank the Lord the GTO could sleep securely in my Mom's garage. Still have that - will die with it.
There will never be another Pontiac. The styling was so different from any other. The sound was different than any other. I dont care what anyone says, pontiac was awesome and always will be. They produced some really super cool cars and there will never be anything like them ever. Ive owned a LeMans, a Grand Prix, a Firebird, a Sunbird and loved everyone of them. My firebird was a 1992. That body style was a head turner. It was metallic blue w/ gray interior. Wow, I miss those days. When cars were exciting and had personalities. You actually would get so anxious to find out what the next Pontiac was going to look like.
We were just kids, but an older friend of ours bought one of these red Trans-Ams, brand new! Then traded it for the cheapest Porsche 914. Even then, we thought he was pretty dumb.
That does blow indeed! But hey, at the same time, 914s are also awesome cars, but yeah, I take it that your friend missed big time for not sticking to the Pontiac. Both are splendid machines in their own ways!
I worked for a Ford dealership during this time frame. I recall the auto hauler delivering new cars to our location when he had to remove a '74 SD the same color but with a red interior and every conceivable option - the hauler driver let me sit in it. I knew its significance then and today.
I had one of these, the '73 Super Duty 455 (7.5 liter) of which only 252 models were built. My engine was rebuilt for street racing (@550 H.P.), and the body was repainted black, with flames and grave yard scenes. It was a great driving car, and I thank God that I did not die while doing so :)
That car is a real gem, I had one from 1970 when I lived in Cow Hollow in San Francisco, and believe it or not sometimes I still dream of driving it, it has stayed under my skin, I will never forget it...!
My favorite Trans Am 455SD Beautiful car I miss Pontiac. I had a 73 Standard 455 . You can still make these motors go fast. My friend has a white standard 455 with the 4x D port heads & runs low 11s with a/c pump gas.
@@camirocz 4X heads are off of the 400ci engine and the smaller combustion chambers really ups the compression on a 455ci......a trick many "in the know" old school poncho guys used to do, myself included. So a high compression and cammed 455ci powered Trans Am going 11's.....high elevens with premium pump gas and a good track with slicks on and suspension dialed in is not that far fetched. I have seen it done actually. I did it myself with the 1973 TA I had, but mine had the 455 SD (Super Duty) engine in it which was nothing like a standard 455. OH, and I upped the 8.5 to 1 compression on that 455SD by putting in different pistons, milling the heads, decking the block....which also required milling the intake manifold and different pushrods.......but, the already potent 455SD responded dramatically well to more compression plus I put a much more aggressive cam in it. You need to realize the 455SD was a special block designed for rigidity at high rpms......even had provisons for dry sump oiling which I never did, but those mods and tweaks added a LOT to that car and low 11's were common for that car. Could have pushed it more with a custom roller cam and such and gotten into the high to mid 10's but I did not want to go that far. So yes, a D port 455 like the commenter said above you shove those 4x or even better the 6x heads on it from a 400ci motor and you have the type of compression they had 1970 and earlier.
Probably my favorite Trans Am ever made. It's between a 73 455SD and a 70 1/2 Ram Air IV. But the RAIV engine didn't have very good street manners from what I understand...so my favorite is probably the 73 455SD. Really like the 74 455SD too...but the 70-73 is the best looking Trans Am in my opinion
George Black I wrecked my 1981 Trans Am, not that it was fast or anything (301), but I got t boned...probably because it was too slow lol. But I am still alive. Thing about metal cars, it can take more of a hit than you can feel inside the car. Tough ass cars. Got me a 79 camaro and 79 Firebird after and I plan on getting a C3 Stingray, preferably 77 and under and a 4 speed manual
Had a 71 challenger back in the day. That bastard nearly killed me twice. Once while racing a GTO, I hit a bump and the dam thing went airborne. Drum brake's sloppy steering a death trap. The TransAm was a refined muscle car in comparison. By the way the GTO beat me, he had an automatic.....
@@tomcannone8894 Yep, Cudas & Challengers Were Great for Strait Line Power,But Even As Far Back As Early GTOs ,Pontiacs Were Better Handlers Around Curves.Friend Of Mine in ATL. Bought Brand New 65 GTO & WE Use To Cruise Thru the Varsity ,Down Street From Ga.Tech & He Liked To Keep A Bottle of Kentucky Tavern in Car ,So I Got To Drive It A Lot to Keep Him OUTA JAIL,& IT Was One of Few Early Muscles That Could Take A Curve @ Speed & Stay On Road.LOL
I remember seeing one of these in 1974 when it drove by my workplace as I was outside at the time. It was white with Blue decals and you couldn't miss that shaker hood scoop with the SD 455 . The front of that car is still stylish enough today to pass as a 2015 design with just a change of headlights to a high powered bulb unit hidden behind a clear plastic cover for better air flow over the hood.
...I had a white 73 non super duty Trans Am...taking the plate off the scoop made it run much better...had the turbo 400 automatic transmission that would chirp the tires ...my only complaint is that it rusted out around the back window...also had 77, 82, 86 Trans Ams and a 94 Formula..Loved my Pontiacs...
Thank you Kevin. Love all your informative posts. Not only did the cars in that era had to drop the compression ratio, they also had EGR to contend with to meet emissions. Pontiac was the only car company to build a truly high performance engine in the smog era.
My friend had a 73 SD Brewster Green automatic with 3:42 gears. He ran Hooker super comp (open) and M&H race master slicks. 13.00 @ 110. I was there. NO other modifcation.
They are bad ass especially for an engine that is kinda held back by emissions equipment. I've heard that in bone stock form and on stock tires they ran 13.5s all day long. Incredible for an engine built in 73
@@jeffwilson4243 yes an open style exhaust freed up a lot of horsepower on those motors......which was why I had a set of cable operated exhaust cutouts to go from full exhaust to wide open when I would race mine back in the day.
not only a great performer for 1973 but the best looking car in '73 because some of us remember those huge ugly bumpers that started in 73 but the firebird for some reason didn't have them even the new front on the '74 looked really good.......
I was 5 when this came out and you saw cars like this everywhere daily. Fascinated with them Babysitter drove a 69 SS 396 Chevelle, aunt drove a Javelin and her boyfriends AMX Today its kids wanting a stang or challenger when they are old enough hope they get the choice and arent forced into an electric pos. Once its in your blood it never leaves ya
How the hell do 19 people not like this car??? Great looking, great handling, and really fast cars. And the amazing part is how Pontiac managed to build a low compression, high performance engine like the 455 super duty while still complying with all the federal emissions standards
What you fail to mention especially about the block is a block had Provisions for a dry-sump oiling this block was designed to be use in NASCAR for the 366 cubic inch limit the heads were also designed by AFR airflow research the main bearing caps were made of malleable iron stronger than cast iron the connecting rods were cap screwed shot peened and magnaflux three times Legend has it that the connecting rods are the strongest connecting rods ever put into a factory engine capable of a thousand horsepower !!!
My friend had a red 73 SD. And I had a black 77 TA. This was in the 80's when muscle cars were $10k and under. We would trade them like baseball cards. Miss those days. These firebird and formula models are still quite affordable, for now. I just sold a running '73 project for $3500!
My brother in law had a gold 1977 TrsnsAm and whenever he would come over I would wash it and detail it. At that time I was a Ford guy but I love that trans am... He would always take me out for a ride in it after I was done cleaning it up....
They don't make cars like this often... Pontiac only made 252 Trans Ams with the 455 Super Duty, in 1973, @ 175 with automatic transmissions, and 75 with manual transmissions. I was able to buy a 1973 Trans Am, with the 455 Super Duty from the original owner, in 1977, and the owner had rebuilt the Super Duty 455 for street racing (800 Holley double pump, with mechanical secondaries, 3/4 street racing cam by Engle, TRW aluminum 10.50 to 1 ratio pistons, Edlebrock aluminum intake, Hooker headers, High Output ignition system, water injection system) and had it custom painted black, with flames and grave yard scenes. (The screaming eagle was replaced on the hood, natch' :) Reminds me of the times when I had engaged in street racing... I thank God that He saved my life :) If you will recall the scene where Burt ran over some mail boxes, try to visualize me in my super duty trans am street racer, out in the sticks being challenged by a car from South Carolina, and the local sheriffs department looking for me, finding me and trying to chase me down, with three of my friends in my car, and clipping 11 fence posts. By God's grace none of us died, including me with a fence post hitting my windshield right next to my head :)
Your car lived a life that was pretty commonplace for cars of this time period and earlier to just get used the heck up. What a gas every inch of the way. Glad you survived that journey.
I had a '73 Super Duty Trans Am (1 of 175 automatics/ 2nd owner) for about 25 years, putting about 20,000 miles on it. It was repainted black with grave yard scenes and flames on it, and had a mean street racing SD 455 rebuilt in it. I thank God that I didn't kill myself, and others, in it :)
Wow, Reminds me of the ‘73 Formula SD455 I had factory ordered, Admiralty Blue. Low gears and HD suspension led me to “drifting” way before there was a name for it… absolute fun! A no-bird sleeper added to the fun times.
310 hp was the pre production number. Once they had to change camshafts it dropped to 290. I really wish they would have made the 73 gto the way it was meant to be built. Sd 455 engine and the grand am front bumper. It would've been one of the greats
over the years I heard rumors now and then of a factory built Super Duty in a Grand Am (1970's full size car) but never ran across one although I looked at several that turned out to be just a regular D port 455 and owner was an idiot and even one someone had swapped in a 455HO into. This was in through out the 1980's when I was into Ponchos heavy.....mainly Trans Ams. Did get a 1973 455SD TA....Brewster Green with tan interior......sold it after my first divorce in 1993......uuuuugh, kick myself for that. BUT in around 1996 I got my first Turbo Buick......a 1986 T Type.......then over the next decade I wound up going through owing 11 1986/87 GN/T Type/Turbo T's and they were all daily driven and taken to the track on test and tune night in the summer every week.....lol. Fastest Turbo Buick was low 11's......back in 1991....still streetable but about all you could go without breaking things or having to put lots of money into it to go faster and lose streetability.......this was with 1991 tech mind you. But even the fastest Turbo Buick was a far cry from that 1973 F body TA with that unibody even with front and rear connected for added stability that thing was like a wild stallion on a hard launch where as the full framed G body Buicks were much tamer.
My '76 Stingray is a 392ci SB stroker, easily outputting 500+HP and a 3.1 sec, 0-60MPH run on a consistent basis. Competition Hi-Perf alum heads, 539/292 (@.500 inch) cam, GM LT-1 performance intake and a 800CFM QuadJet coupled with a highly stiffened TH700R4 (2200 RPM stall) trans and 3.90:1 ring & pinion gets this car out of the way in a hurry... and the best part is I'm not around for burnouts!!! My car squats & trots, or for some, shits & gits!!!!!!!! Cannot wait for the winter to end...
That is my second favorite car of all time well not the 73 but the 70 although I might change my mind after seeing this video I had no idea that any 73 car had any kind of balls at all or look that good I am in shock
+MFSB - I think the government was running some kind of campaign that made everyone believe that muscle cars were "bad." I also wonder how much advertising GM allowed Pontiac to do for this car. Pontiac always seemed to me to be the rebellious teenager of the GM family. *LOL* Pontiacs may have generally always been the same as Chevy underneath, but the Pontiacs always looked better and performed better then their Chevrolet cousins.
+knytrydr73 pontiacs were superior to chevy when it came to powerplants. theres a reason the enthusiast crowd still exist 35 years after the last Pontiac motor was produced.
MFSB No one wanted to drive a gas hog by late 1973 when gas was already over a $1 a gallon insurance rates already scared of potential buyers and yes some people viewed muscle cars as bad or joke cars.
I was a kid when these were out, my cuz, b4 going to 'Nam got 1 'cept his was a manual transmission. My dad had a '73 Buick Riviera GS 455 Stage 1. I had no license & would sneak the Buick out,& just blow the doors of so-called new muscle cars, even Cadillac,& Lincolns, T-birds, etc...that T/A SD455 4spd wasn't 1 of them. All I was able to see was his brake lights. We had SAFE fun back then. He lost it @ a Pathmark supermarket big parking lot to thieves. Never to be seen again. But, many had fun with it. It was awesome. 🥊
A friend of mine had this car. Beautiful car: Red w/Black leather, Power windows (Two switches in the middle console), A/C, [at 90 mph it was as if a passing gear kicked in] It would set you back in the seat letting you know it's no doubt a big block. Loved it! The 4 speed gave it a 12 - 13 second quarter mile time...stock. Took totally built cars to give it a run & even at that, you had better be able to drive...He unfortunately depended on the power once too often and totalled it in '75 crossing Hwy 6...so mark that one off the few left. The good news...40 year's later he got another one! Gotta love it! BTW...same guy got a '74 as a replacement back then. It was a huge disappointment and later bought himself a pick up.
The 74 was rarer than the 73 since the front end and rear end was a one year body style whereas the 70-73 cars were pretty much identical. I do prefer the 74 all day
@@lennon992 your a dumbass. Do your homework, the 310 hp was with a 041 ram air 4 spec cam. None were produced with the K cam. All production engines all, let me reiterate ALL for 73&74 had ram air 3 spec cams which is the 744 cam 290 hp for all SD 455s. I have a 74 SD auto, my friend has a 73 SD auto and his brother has a 74 SD manual. What do you have?! They All have the Y cam in them which has the same spec's as the 744 cam. I wished they cam with the K cam.
Awesome, 3 of you guys with an SD 455. I have one too. Got rid of the Y cam ( sitting in a box now) and had a Nunzi Ram Air IV style cam put in to take its place. Wow talk about waking the bad boy up. Mine is an THM400 car with a rejetted carb, distributor recurve and I have a separate shaker that is open to use as well. Just bad ass. Have owned it for about 10 years now. @@jeffwilson4243
This is one great body design. Best body style of the trans am. This car in stock form was pretty fast. I had the misfortune of racing a guy that had one of these with 50 series tires stuffed inside its wheel wells. He had a big block Chevy in it and he really got me. That's what happens when a 12 sec car races a 13 sec car.
It took me awhile to piece it all together. I had to remember my childhood in the 70s. Here we go, nobody bought a muscle car and left it stock. The reason numbers matching stock engines are rarer than the cars is because it was not the norm. Racing from the 50s to the 80s was everything. From motocross to snowmobiles to drag racing. Everyone did it. There were multiple performance shops in cities of 40 thousand people. Everyone ported heads and cam swapped with shift kits headers and converters. That was the baseline. 455 SD guys are milling the heads. Angle milling was huge for the low compression motors. Anyway, that's why everyone remembers muscle cars being fast. Because they were. Most cars were in the 10s or 11s. I went to the drags all summer long. Look how big the stands are. They were full all the time. All the kids cruising around town were there running their cars. In 77 a guy named Frenchie took me for a rip in a70h 72 grand Torino modded 429. Up to 100 in 5 seconds. I was 7, I'll never forget that one. Here hold my stopwatch, hit the button when I say yep. Bam 5 seconds including my reaction time.
A family friend had one of these Trans Ams, not sure if it was a SD but it was red and had a 455. He traded it in for a Corvette and later said he regretted it...
What a fantastic channel this is. Actual content, facts and knowledge. Not some fucking millennial walking around his new $100k sportscar daddy bought him, talking nonsense and getting coffee for 45 minutes...
I owned a Black on Black Velour '78 W-72 T/A with a functional Shaker. Nothing sounds quite as satisfying. Three engines, Two transmissions and Two rear ends later I finally sold it. I've regretted it every since.
I'm 75 yrs . old. In the early 80s I had a '76 SD455 4 speed Trans Am. Like a damn fool I sold it to a guy who crashed it. I tried to buy back the engine but it didn't work out.
I think the Chevy 454 was rated even lower than that. The 455SD was easily the fastest car you could buy in 1973-74. The 73 340 Plymouth Duster/Dodge Dart Sport's were pretty quick but nothing like an SD Trans Am. Pontiac should've offered the 455SD as an option in the 73-74 GTO too. The 74 GTO compact would've been one of the fastest muscle cars ever made with the 455SD under the hood...seeing how it was 500 lbs lighter than a 74 Trans Am and a 74 455SD T/A was capable of mid 13's in the 1/4 mile. A 74 GTO SD455 probably would've been a high 12-very low 13 second car.
because of muscle cars like these and the Buick Grand National to follow years later, the 'Muscle Car Era' was never REALLY over...just sidelined for a while....just look at all the ground-pounding, smoke the rubber off the wheels Modern Muscle cars around today! 'nuff said
I have a red 70' Formula 400 and I have done a few upgrades for performance , upgraded exhaust and headers , HEI dist. and a good tune and she's fast and I can only imagine what it would be like with a SD 455 ! what a monster they must be ! I bet a lot were sold back in the day because of getting tickets , high insurance costs and the Cops watching you very closely every time you took it out on the road ! And the only way they would catch you is because they have radios to call for some help !
Also in 1973 it was the last year for the Convertible on many sports cars to lose the open air fun to cruise the streets on a warm night. The new safety rules for Rolls made it too tough to build a soft top that didn't tax the Motor for the weight and was rigid while up to carry the load of the car if it rolled over in a crash . The Mustang and Cougar conv's ended in 73 plus the galaxie was 1972 while the Eldorado bowed out in 1976 with just 2 more years as a hard top before that long huge version drove into the sunset along with the 501 CID engine.
Beautiful car I miss Pontiac so much
It was the best division of GM, Chevrolet was a close second.
My understanding is that those super duty 455 heads even flowed better than the Chrysler Hemi. These cars were easily the fastest of their day. Thank you for the attention you gave to this historical car!
+Barcrrt Can you show me the source for your claim? Hemi engine has cross flow heads that no wedge can match sorry.
Shawn Riddle
popular hotrodding December 1972 issue mentions that the SD heads flow better than the hemi heads. Air Flow Research helped to design the heads. I'm sure you heard of them.
Jeff Wilson I also saw something on a video about the SD head's feeling better than the Hemi. I tried to find it on RUclips but couldn't. It is out there somewhere...
Barcrrt
Best all-around musclecar package ever.
I owned a73’ Tran Am ( Brewster green / tan interior) and I wish I never gave it up. I took that car pass 160 on speed and still had more. Thank goodness for great handling. You all have a great day.
160 mph?? Come on let's be real here.
@@maximumcoverage5591 Dude...that is real. My father had a 1974 just the normal 455 (no SD) and my older brother , with me in the passenger seat, took it 165 and he let up cause were starting to get spooked. It would have gone faster. You ever been in a vintage T/A?
@@saltydog4759 yup and had a 455 in an Olds cutlass SX as well. I ain't believing it until I see it with a cop radar. I'm not saying the gage didn't read 160, and those things mostly had highway gears unless you special ordered something higher. I've been 160 for sure on motorcycles more than several times, my buddy in high school had a formula 400, no way would that thing hit 160, maybe 120, maybe. Been that fast in a Porsche 911 Turbo and that was smooth as F, both as a passenger and driving it. Been riding in some old cars that looked over 130 on the speedo, every time that needle would sure have some bounce to it. So the chance that they all or even many could go 160. I have a hard time believing that bro. It's really fast. What year was your Dad's and was it automatic or stick?? That must have been the shit to grow up riding in. Lol my one grandmother was a mustang fan, she had a 73 riveria wa 455 and that thing was solid at like 110-120, after a rebuild with more compression and my grandpa putting hollowed out cats on the exhaust. Some bikers were messing with my grandma one day on the highway. So she started going faster until the speedo was buried in her 429 equipped Ford wagon. She said they couldn't hang at 120 and one slowed down to fast and ate it in the median and the other guy she crowded enough so he backed off her. She told my grandpa that she wanted that kind of power in every car she drove. She had 4 kids and a dog and all thier crap in the wagon at the time. What I'm saying is the difference between 120-130 and 160 is a lot, and saying the majority of 455 TA could do 160 is unrealistic bro.
@@maximumcoverage5591 I asked my older brother who was driving that day and he told it me was 143 MPH or so. Just under 145 So, since he was driving that day so many years ago, I'll defer to his memory! Although he did say he let up, but felt it had more in it when he did. I guess I stand corrected. I was only 16 at the time so maybe the number grew in my head over the decades!
Top speed back then had much less to do with Horsepower, and everything to do with gearing. '73 T/A with Firestone "wide 60 ovals" were 25.9" tall, the Automatics had 3.08 rear ends, the 4 Spd 3.42 Redline was 5700 RPM. At 5700 RPM an Automatic car would be 143mph and a 4 spd car would top out at 128! Would they Rev past 5700?, sure but could you Rev it to the required 7300 RPM to get 165 mph in a 4 Spd car? NO WAY! Cars back then were not built for top speed.
I had a 1973 Formula Firebird that was beautiful, but had the 'smoggy' 400 in it. I pulled the weak 400, took a 455 from a Grand Safari wagon, pulled the internals, replaced with a forged crank and rods, '4-brow' pistons, and the AMAZING '46' head stamp heads form a 1968 Pontiac 428 Police Interceptor...along with a 'purple stick' 428 OEM cam. Machinist that did the block work for me said he calculated 10.7:1 compression. Engine dyno'd 571-hp, 602-torque with a 1070-holley on a dual plane Edelbrock intake...and just like that, it went into my 73 Formula...and off to the track we went. The car turned 10.7's pretty consistently at 132-mph, give or take (depending on the weather and temps), with a shift-kitted 400-Turbo automatic. Why does this matter? Because Pontiac COULD HAVE EASILY built this engine in 1970 for the Trans Ams...and didn't...because GM MANDATED that no subdivision of GM could make a car that OUT-PERFORMED the LS6 Corvettes...that's why!
Well done.
Thought the LS6 Corvette Eng.Was 425 ,Compared to the 450h.p.of the LS6 70 Chevelle,Which Most Say Are Really Closer to 500 h.p.
I think only Chevelle SS had the LS6 in 1970 and only the Corvette had it in 71. But the 71 LS6 was a lower compression version
I think but I could be wrong though
@@jeremythompson9895 You're absolutely correct, sir. The Chevelle was the sole vehicle (except it's half-twin the El Camino) to get the 450hp LS-6 in '70, and in '71 the compression was reduced (along with the power output).
The fact is, there were never any "mandates" keeping the corvette on top of the performance hill at GM. Its light weight and large engine bay did that.
I still miss mine. Ordered it brand new before I graduated engineering and didn't have to make a payment until September. All the banks in Blacksburg had to see was your employment offer letter with a start date. It was not an SD, and I was very disappointed when it arrived as my '66 GTO would run rings around it. With a bit of wrenching it was soon going 12 second @ 120s quarter miles. Alas in 1978 life took priority and I had to sell it. Thank the Lord the GTO could sleep securely in my Mom's garage. Still have that - will die with it.
There will never be another Pontiac. The styling was so different from any other. The sound was different than any other. I dont care what anyone says, pontiac was awesome and always will be. They produced some really super cool cars and there will never be anything like them ever. Ive owned a LeMans, a Grand Prix, a Firebird, a Sunbird and loved everyone of them. My firebird was a 1992. That body style was a head turner. It was metallic blue w/ gray interior. Wow, I miss those days. When cars were exciting and had personalities. You actually would get so anxious to find out what the next Pontiac was going to look like.
This SD455 TA is so beautiful!!
We were just kids, but an older friend of ours bought one of these red Trans-Ams, brand new! Then traded it for the cheapest Porsche 914. Even then, we thought he was pretty dumb.
That does blow indeed! But hey, at the same time, 914s are also awesome cars, but yeah, I take it that your friend missed big time for not sticking to the Pontiac. Both are splendid machines in their own ways!
Funny now are the prices of 914 Porches today.
This is my holy grail, you can keep all the split bumper Camaros, I'm taking this every time, even over the much more valuable 1st gen Trans Am.
The only Split Bumper Camaro that's comparable, or in the same rare air, is the 70 L78, the rest don't come even close.
I'll have one of each please. But make my Bird a formula. I like that dual snorkel hood, best hood ever.
I worked for a Ford dealership during this time frame. I recall the auto hauler delivering new cars to our location when he had to remove a '74 SD the same color but with a red interior and every conceivable option - the hauler driver let me sit in it. I knew its significance then and today.
I had one of these, the '73 Super Duty 455 (7.5 liter) of which only 252 models were built. My engine was rebuilt for street racing (@550 H.P.), and the body was repainted black, with flames and grave yard scenes. It was a great driving car, and I thank God that I did not die while doing so :)
Why'd you sell it
Sacrilege I guess that was a 70s thing 😵
@@deanwilliams867 lol I was reading that thinking "my god that is a criminal offense to do to that car"
That car is a real gem, I had one from 1970 when I lived in Cow Hollow in San Francisco, and believe it or not sometimes I still dream of driving it, it has stayed under my skin, I will never forget it...!
SD455 auto is still one of the most thrilling cars to drive ever
My favorite Trans Am 455SD Beautiful car I miss Pontiac. I had a 73 Standard 455 . You can still make these motors go fast. My friend has a white standard 455 with the 4x D port heads & runs low 11s with a/c pump gas.
Low 11s with 4 x heads?Doubt it very much.Maybe a stroked engine with aluminum heads.
@@camirocz 4X heads are off of the 400ci engine and the smaller combustion chambers really ups the compression on a 455ci......a trick many "in the know" old school poncho guys used to do, myself included. So a high compression and cammed 455ci powered Trans Am going 11's.....high elevens with premium pump gas and a good track with slicks on and suspension dialed in is not that far fetched. I have seen it done actually. I did it myself with the 1973 TA I had, but mine had the 455 SD (Super Duty) engine in it which was nothing like a standard 455. OH, and I upped the 8.5 to 1 compression on that 455SD by putting in different pistons, milling the heads, decking the block....which also required milling the intake manifold and different pushrods.......but, the already potent 455SD responded dramatically well to more compression plus I put a much more aggressive cam in it. You need to realize the 455SD was a special block designed for rigidity at high rpms......even had provisons for dry sump oiling which I never did, but those mods and tweaks added a LOT to that car and low 11's were common for that car. Could have pushed it more with a custom roller cam and such and gotten into the high to mid 10's but I did not want to go that far. So yes, a D port 455 like the commenter said above you shove those 4x or even better the 6x heads on it from a 400ci motor and you have the type of compression they had 1970 and earlier.
Probably my favorite Trans Am ever made. It's between a 73 455SD and a 70 1/2 Ram Air IV. But the RAIV engine didn't have very good street manners from what I understand...so my favorite is probably the 73 455SD. Really like the 74 455SD too...but the 70-73 is the best looking Trans Am in my opinion
Very good taste Sir!
I had a 1973 Trans Am with a 455 Super Duty (1 of 252), built for street racing, for @ 25 years. By God's grace I am still alive :)
George Black I wrecked my 1981 Trans Am, not that it was fast or anything (301), but I got t boned...probably because it was too slow lol. But I am still alive. Thing about metal cars, it can take more of a hit than you can feel inside the car. Tough ass cars. Got me a 79 camaro and 79 Firebird after and I plan on getting a C3 Stingray, preferably 77 and under and a 4 speed manual
And I'm just 20 yeard old
Had a 71 challenger back in the day. That bastard nearly killed me twice. Once while racing a GTO, I hit a bump and the dam thing went airborne. Drum brake's sloppy steering a death trap. The TransAm was a refined muscle car in comparison. By the way the GTO beat me, he had an automatic.....
@@tomcannone8894 Yep, Cudas & Challengers Were Great for Strait Line Power,But Even As Far Back As Early GTOs ,Pontiacs Were Better Handlers Around Curves.Friend Of Mine in ATL. Bought Brand New 65 GTO & WE Use To Cruise Thru the Varsity ,Down Street From Ga.Tech & He Liked To Keep A Bottle of Kentucky Tavern in Car ,So I Got To Drive It A Lot to Keep Him OUTA JAIL,& IT Was One of Few Early Muscles That Could Take A Curve @ Speed & Stay On Road.LOL
I remember seeing one of these in 1974 when it drove by my workplace as I was outside at the time. It was white with Blue decals and you couldn't miss that shaker hood scoop with the SD 455 .
The front of that car is still stylish enough today to pass as a 2015 design with just a change of headlights to a high powered bulb unit hidden behind a clear plastic cover for better air flow over the hood.
Back then the government still mandated round headlights.
...I had a white 73 non super duty Trans Am...taking the plate off the scoop made it run much better...had the turbo 400 automatic transmission that would chirp the tires ...my only complaint is that it rusted out around the back window...also had 77, 82, 86 Trans Ams and a 94 Formula..Loved my Pontiacs...
Probably the nicest Pontiac T/A I have seen. As a bonus, the Fire-Chicken looks good in these colors to! ~Thanks for posting!
Fester Adams right
Thank you Kevin. Love all your informative posts.
Not only did the cars in that era had to drop the compression ratio, they also had EGR to contend with to meet emissions. Pontiac was the only car company to build a truly high performance engine in the smog era.
Oh my what a beautiful beautiful car! I had a 1976 Trans Am but by that time they weren't much of a performance car! But they were still beautiful
Those 73/74 T/A SD's with a set of DR's were high 12sec @107mph all day long..without a doubt the best Trans Am's ever produced
Soon2Be Fulfilled wow..i figured the 69 or 70 1/2 400 ram air iv would be the best.
My friend had a 73 SD Brewster Green automatic with 3:42 gears. He ran Hooker super comp (open) and M&H race master slicks. 13.00 @ 110. I was there. NO other modifcation.
Nice
They are bad ass especially for an engine that is kinda held back by emissions equipment. I've heard that in bone stock form and on stock tires they ran 13.5s all day long. Incredible for an engine built in 73
@@jeffwilson4243 yes an open style exhaust freed up a lot of horsepower on those motors......which was why I had a set of cable operated exhaust cutouts to go from full exhaust to wide open when I would race mine back in the day.
I’m a Camaro guy but damn those trans am are alluring...
Absolutely top-level videos, great narration and lots learned - great job guys!
BAD ASS LINES AND A BAD ASS POWER PLANT BAD ASS INTERIOR.... WISH THEY STILL MADE THEM LIKE THIS.
Once again the best RUclips video. Thanks...!
not only a great performer for 1973 but the best looking car in '73 because some of us remember those huge ugly bumpers that started in 73 but the firebird for some reason didn't have them even the new front on the '74 looked really good.......
I was 5 when this came out and you saw cars like this everywhere daily. Fascinated with them
Babysitter drove a 69 SS 396 Chevelle, aunt drove a Javelin and her boyfriends AMX
Today its kids wanting a stang or challenger when they are old enough hope they get the choice and arent forced into an electric pos. Once its in your blood it never leaves ya
Breathtakingly Beautiful
The Muscle Car market is just at its cusp of becoming even wilder. Gosh, these cars have aged so beautifully.
My favorite muscle car eva 73 Trans Am.
Legend has It as soon as you start her up you grow a mullet.
My god that’s my dream car!!🥳🤩🥰
Well stated Bob Stinson. I think we would all like 30 minute videos when dealing with such a rare bird or other unique classic. P.S. Love the Trans Am
Dean Coleman sexy women Maserati Porsche Cayenne Ferrari corvette
How the hell do 19 people not like this car??? Great looking, great handling, and really fast cars. And the amazing part is how Pontiac managed to build a low compression, high performance engine like the 455 super duty while still complying with all the federal emissions standards
POSERS!!!
STUPID...
Beautiful Car I like the 70 to 73 style TA the best.
Mike Boon: Agreed
That's a fantastic car. What a beauty!
I really want an SD 455.
What a beautiful color
My friends dad has this same 73, white interior buccaneer red with the 4 speed in it. Stunning car! Got to ride in it only once.
Very beautiful vehicle.
Wow..i thought the 70 1/2 Ram Air iv was the last of the great Trans Ams. Nice video!
Beauty and the beast together as one
Will always pine over the Super Duties. If I could get just an SD block and build it for my '69 Firebird, I'd be a happy man
What you fail to mention especially about the block is a block had Provisions for a dry-sump oiling this block was designed to be use in NASCAR for the 366 cubic inch limit the heads were also designed by AFR airflow research the main bearing caps were made of malleable iron stronger than cast iron the connecting rods were cap screwed shot peened and magnaflux three times Legend has it that the connecting rods are the strongest connecting rods ever put into a factory engine capable of a thousand horsepower !!!
And all fed by a quadrajet. Was and still is excellent for street use.
Das ist kein Auto , das ist Kunst !! 👍
Right!
My friend had a red 73 SD. And I had a black 77 TA. This was in the 80's when muscle cars were $10k and under. We would trade them like baseball cards. Miss those days. These firebird and formula models are still quite affordable, for now. I just sold a running '73 project for $3500!
😢
My brother in law had a gold 1977 TrsnsAm and whenever he would come over I would wash it and detail it. At that time I was a Ford guy but I love that trans am... He would always take me out for a ride in it after I was done cleaning it up....
Thanks for making these videos, I enjoy them a lot! Specially this one with this hot T/A!
I love these body styles
Jus Fadezz 70-81 body. 74, last year of the smaller back window
Thanks for the Video missing the Bird!
Now that’s a work of art
The dash is one of GM's best
They don't make cars like this often... Pontiac only made 252 Trans Ams with the 455 Super Duty, in 1973, @ 175 with automatic transmissions, and 75 with manual transmissions. I was able to buy a 1973 Trans Am, with the 455 Super Duty from the original owner, in 1977, and the owner had rebuilt the Super Duty 455 for street racing (800 Holley double pump, with mechanical secondaries, 3/4 street racing cam by Engle, TRW aluminum 10.50 to 1 ratio pistons, Edlebrock aluminum intake, Hooker headers, High Output ignition system, water injection system) and had it custom painted black, with flames and grave yard scenes. (The screaming eagle was replaced on the hood, natch' :)
Reminds me of the times when I had engaged in street racing... I thank God that He saved my life :) If you will recall the scene where Burt ran over some mail boxes, try to visualize me in my super duty trans am street racer, out in the sticks being challenged by a car from South Carolina, and the local sheriffs department looking for me, finding me and trying to chase me down, with three of my friends in my car, and clipping 11 fence posts. By God's grace none of us died, including me with a fence post hitting my windshield right next to my head :)
Your car lived a life that was pretty commonplace for cars of this time period and earlier to just get used the heck up. What a gas every inch of the way. Glad you survived that journey.
The firebird cars are precious.😊
I had a '73 Super Duty Trans Am (1 of 175 automatics/ 2nd owner) for about 25 years, putting about 20,000 miles on it. It was repainted black with grave yard scenes and flames on it, and had a mean street racing SD 455 rebuilt in it. I thank God that I didn't kill myself, and others, in it :)
Beautiful Ride!
Wow, Reminds me of the ‘73 Formula SD455 I had factory ordered, Admiralty Blue.
Low gears and HD suspension led me to “drifting” way before there was a name for it… absolute fun! A no-bird sleeper added to the fun times.
Great review!
310 hp was the pre production number. Once they had to change camshafts it dropped to 290. I really wish they would have made the 73 gto the way it was meant to be built. Sd 455 engine and the grand am front bumper. It would've been one of the greats
over the years I heard rumors now and then of a factory built Super Duty in a Grand Am (1970's full size car) but never ran across one although I looked at several that turned out to be just a regular D port 455 and owner was an idiot and even one someone had swapped in a 455HO into. This was in through out the 1980's when I was into Ponchos heavy.....mainly Trans Ams. Did get a 1973 455SD TA....Brewster Green with tan interior......sold it after my first divorce in 1993......uuuuugh, kick myself for that. BUT in around 1996 I got my first Turbo Buick......a 1986 T Type.......then over the next decade I wound up going through owing 11 1986/87 GN/T Type/Turbo T's and they were all daily driven and taken to the track on test and tune night in the summer every week.....lol. Fastest Turbo Buick was low 11's......back in 1991....still streetable but about all you could go without breaking things or having to put lots of money into it to go faster and lose streetability.......this was with 1991 tech mind you.
But even the fastest Turbo Buick was a far cry from that 1973 F body TA with that unibody even with front and rear connected for added stability that thing was like a wild stallion on a hard launch where as the full framed G body Buicks were much tamer.
My '76 Stingray is a 392ci SB stroker, easily outputting 500+HP and a
3.1 sec, 0-60MPH run on a consistent basis. Competition Hi-Perf alum
heads, 539/292 (@.500 inch) cam, GM LT-1 performance intake and a 800CFM
QuadJet coupled with a highly stiffened TH700R4 (2200 RPM stall) trans
and 3.90:1 ring & pinion gets this car out of the way in a hurry...
and the best part is I'm not around for burnouts!!! My car squats &
trots, or for some, shits & gits!!!!!!!! Cannot wait for the winter
to end...
Team "fuck winter!!" Because michigan up here is like Canada and $#!7
This Is My All Favorite Time Screaming Muscle Raw Power Car! That Is A Car That Can Haul Some Serious Ass!
Coolest dash ever. Those 2nd gen F bodies were the best driving musclecars ever.
my buddy had this car with a 4 speed 20 years ago.sick
It looks like I won't be owning any of these cars in my life-time, I'm glad somebody kicked ass enough to obtain these cars.
Never say never
I always love seeing SD, on the scoop. This car is beautiful. $6k in 1973, is about $40k today. Yeah, I'd buy it
Absolutely Feckin Awesome
That is my second favorite car of all time well not the 73 but the 70 although I might change my mind after seeing this video I had no idea that any 73 car had any kind of balls at all or look that good I am in shock
1973 was a high water mark for Pontiac F-body styling. I'll never understand why they didn't sell more.
+MFSB - I think the government was running some kind of campaign that made everyone believe that muscle cars were "bad." I also wonder how much advertising GM allowed Pontiac to do for this car.
Pontiac always seemed to me to be the rebellious teenager of the GM family. *LOL* Pontiacs may have generally always been the same as Chevy underneath, but the Pontiacs always looked better and performed better then their Chevrolet cousins.
+knytrydr73 pontiacs were superior to chevy when it came to powerplants. theres a reason the enthusiast crowd still exist 35 years after the last Pontiac motor was produced.
if you listened to the first 28 seconds of this video, you'd understand why they didn't sell more...
MFSB right. Stingray lasted to 1982, but the 70s f body only went to 81
MFSB No one wanted to drive a gas hog by late 1973 when gas was already over a $1 a gallon insurance rates already scared of potential buyers and yes some people viewed muscle cars as bad or joke cars.
think John Wayne drove one in a movie --- not sure --- but it was badass
I was a kid when these were out, my cuz, b4 going to 'Nam got 1 'cept his was a manual transmission. My dad had a '73 Buick Riviera GS 455 Stage 1. I had no license & would sneak the Buick out,& just blow the doors of so-called new muscle cars, even Cadillac,& Lincolns, T-birds, etc...that T/A SD455 4spd wasn't 1 of them. All I was able to see was his brake lights. We had SAFE fun back then. He lost it @ a Pathmark supermarket big parking lot to thieves. Never to be seen again. But, many had fun with it. It was awesome. 🥊
Buick 455's and even the regular Pontiac 455's were different motors from the SD 455's, parts weren't interchangeable.
Now its more popular now then it was back in 1973.
I like it. My dad had a 1970 firebird. I had a cousin who had a SD TransAm but it was a later year. Still a cool car in 1978 or so...
71-73 TA, my Favorite.
One of the best American cars ever made.
A friend of mine had this car. Beautiful car: Red w/Black leather, Power windows (Two switches in the middle console), A/C, [at 90 mph it was as if a passing gear kicked in] It would set you back in the seat letting you know it's no doubt a big block. Loved it! The 4 speed gave it a 12 - 13 second quarter mile time...stock. Took totally built cars to give it a run & even at that, you had better be able to drive...He unfortunately depended on the power once too often and totalled it in '75 crossing Hwy 6...so mark that one off the few left. The good news...40 year's later he got another one! Gotta love it! BTW...same guy got a '74 as a replacement back then. It was a huge disappointment and later bought himself a pick up.
The 74 was rarer than the 73 since the front end and rear end was a one year body style whereas the 70-73 cars were pretty much identical. I do prefer the 74 all day
The 1974 has the exact same engine. ALL 73&74 SDs had the same 290 HP engine. Don't believe me, do some research!
Jeff Wilson Nope 73' had 310 hp
@@lennon992 your a dumbass. Do your homework, the 310 hp was with a 041 ram air 4 spec cam. None were produced with the K cam. All production engines all, let me reiterate ALL for 73&74 had ram air 3 spec cams which is the 744 cam 290 hp for all SD 455s. I have a 74 SD auto, my friend has a 73 SD auto and his brother has a 74 SD manual. What do you have?! They All have the Y cam in them which has the same spec's as the 744 cam. I wished they cam with the K cam.
Awesome, 3 of you guys with an SD 455. I have one too. Got rid of the Y cam ( sitting in a box now) and had a Nunzi Ram Air IV style cam put in to take its place. Wow talk about waking the bad boy up. Mine is an THM400 car with a rejetted carb, distributor recurve and I have a separate shaker that is open to use as well. Just bad ass. Have owned it for about 10 years now. @@jeffwilson4243
I was in love with the 1977 bu I may have just changed my mind.
Beautiful car :-)
This is one great body design. Best body style of the trans am. This car in stock form was pretty fast. I had the misfortune of racing a guy that had one of these with 50 series tires stuffed inside its wheel wells. He had a big block Chevy in it and he really got me. That's what happens when a 12 sec car races a 13 sec car.
BB chevy??
de lo mejor de lo mejor en autos de poder... los hombres nacidos en los 70' los buscamos ahora
I agree totally with the styling, gorgeous car
Ciao tu parli italiano di dove sei tu del italia ? Io di palermo e tu ?
It took me awhile to piece it all together. I had to remember my childhood in the 70s. Here we go, nobody bought a muscle car and left it stock. The reason numbers matching stock engines are rarer than the cars is because it was not the norm. Racing from the 50s to the 80s was everything. From motocross to snowmobiles to drag racing. Everyone did it. There were multiple performance shops in cities of 40 thousand people. Everyone ported heads and cam swapped with shift kits headers and converters. That was the baseline. 455 SD guys are milling the heads. Angle milling was huge for the low compression motors.
Anyway, that's why everyone remembers muscle cars being fast. Because they were. Most cars were in the 10s or 11s. I went to the drags all summer long. Look how big the stands are. They were full all the time. All the kids cruising around town were there running their cars. In 77 a guy named Frenchie took me for a rip in a70h 72 grand Torino modded 429. Up to 100 in 5 seconds. I was 7, I'll never forget that one. Here hold my stopwatch, hit the button when I say yep. Bam 5 seconds including my reaction time.
Excellent video Thank You...& one sweet ride,..damn...Im droolin here.
yep Video crashes at 1:33
A family friend had one of these Trans Ams, not sure if it was a SD but it was red and had a 455. He traded it in for a Corvette and later said he regretted it...
Got to give it to Pontiac, keeping the muscle car alive when most manufacturers were decal packages only.
What a fantastic channel this is. Actual content, facts and knowledge. Not some fucking millennial walking around his new $100k sportscar daddy bought him, talking nonsense and getting coffee for 45 minutes...
Thank you!
I owned a Black on Black Velour '78 W-72 T/A with a functional Shaker. Nothing sounds quite as satisfying. Three engines, Two transmissions and Two rear ends later I finally sold it. I've regretted it every since.
Beautiful
I'm 75 yrs . old. In the early 80s I had a '76 SD455 4 speed Trans Am. Like a damn fool I sold it to a guy who crashed it. I tried to buy back the engine but it didn't work out.
remember these on the streets in mid 70s
Best looking TransAm 2nd gen.
Yeah that car is amazing for 1973 with 310 HP, i think the chev 454 was 270 HP that year
I think the Chevy 454 was rated even lower than that. The 455SD was easily the fastest car you could buy in 1973-74. The 73 340 Plymouth Duster/Dodge Dart Sport's were pretty quick but nothing like an SD Trans Am. Pontiac should've offered the 455SD as an option in the 73-74 GTO too. The 74 GTO compact would've been one of the fastest muscle cars ever made with the 455SD under the hood...seeing how it was 500 lbs lighter than a 74 Trans Am and a 74 455SD T/A was capable of mid 13's in the 1/4 mile. A 74 GTO SD455 probably would've been a high 12-very low 13 second car.
The 1973 454 was rated 270 hp in the Corvette only. Every other car with a 454 had 235 hp standard.
handling was only top notch,when the WS6 handling package appeared,which i believe was around '76.
because of muscle cars like these and the Buick Grand National to follow years later, the 'Muscle Car Era' was never REALLY over...just sidelined for a while....just look at all the ground-pounding, smoke the rubber off the wheels Modern Muscle cars around today! 'nuff said
G bodies aren't muscle cars
I have a red 70' Formula 400 and I have done a few upgrades for performance , upgraded exhaust and headers , HEI dist. and a good tune and she's fast and I can only imagine what it would be like with a SD 455 ! what a monster they must be ! I bet a lot were sold back in the day because of getting tickets , high insurance costs and the Cops watching you very closely every time you took it out on the road ! And the only way they would catch you is because they have radios to call for some help !
Love it!
Also in 1973 it was the last year for the Convertible on many sports cars to lose the open air fun to cruise the streets on a warm night. The new safety rules for Rolls made it too tough to build a soft top that didn't tax the Motor for the weight and was rigid while up to carry the load of the car if it rolled over in a crash .
The Mustang and Cougar conv's ended in 73 plus the galaxie was 1972 while the Eldorado bowed out in 1976 with just 2 more years as a hard top before that long huge version drove into the sunset along with the 501 CID engine.
I've had an 81 TA, 79 Camaro, and 79 Firebird..best I could get for the money lol
...thanks so much
Very nice