i still have a set of mac flow path mufflers on my 91 lx since the 90s and i love them .using mac equal length headres .with bbk no cats h pipe .i actualy took off the old 40 series flow masters and love the mac so much better ...i even gained 2 tenths on the quarter mile just from swpping out the mufflers test done in 1998 ...yes i own the 91 33 years bought her new
What's good KASL, LOVE YOUR CHANNEL I have a brand new still in the box, 3 inch mac pro chamber for (LONG TUBE HEADERS)... I'M PRETTY SURE IT'S THE HOLY GRAIL😊.. might consider selling it.
i use the flow path mufflers and i have loved them since 1998 they sound awesome and perform amazing and yes i bought 2 sets of mufflers i stll have a brand new set still in the boxes in my house garage
I have a brand new set of 351W 1 7/8 jet hot coated shorties in the box. It took MAC over 9 months to get them to me. One day I'll find a project home for them.
I had a pair of short stainless mac headers on my 93 notch back with mac x-pipe with single stage flowmasters and it was the absolute best sounding exhaust ive ever had and dare say ever heard on a fox body.
I’ve had at least 5 different sets of Mac headers 20 years ago or more. I never had an alignment issue. The alignment issues with them usually were with using the stock bolts and those ridiculously large heads and built-in washers. The washers were usually the culprit for misalignment. Using smaller header bolts was always a win for me so I never bothered with factory bolts. Mac headers were great, especially if they were coated. I still have a 3” Power Chamber but it’s not being used. It may go back on when the stroker Cleveland goes in, but that’ll be later this year. Great video
I got one of them sets on my stang. Yeah 240 bucks, and i did have a fitment issue with the last bolt hole on no 8 cylinder. Had to enlarge the hole to get the bolt in. Bought them back in 94 and still have them on thecar today. Had one of their no cats H pipe that rusted within a year. That was disappointing. Thanks for the memories.
MAC never impressed me with their quality but to their credit, they seemed to make a header for every conceivable combination. Example, TFS high port heads on a 351 with a Lakewood bellhousing, big primaries and alternate bolt pattern. Okay, I'm not sure they specifically offered headers for exactly that, but they seemed to really try to cater to everyone. I never liked the individual flange design, but in retrospect it might have been a good idea. It seems like they would flex more and seal better like the factory headers that are the same way. You never had bolts backing out of those.
@@KASLCustoms when I had to reinstall my headers like a yr n a half ago only way I was able to get the last 2 bolts in was a big pry bar and a prayer, the relief after wrestling with it for like an hr was so sweet lol.
@@KASLCustoms Won't help with these specific headers but try using studs for heads. They have the small non threaded part that locates manifold holes nicely and use as much thread as possible for less point load stress.
1) Mac did make specific GT40P headers, 1 set for Foxes & a separate set specific for the '94-'95 Mustang. I have a brand new set of Mac Fox "P" headers I bought not long before they shut down. 2) I also have a brand new set of Mac 1 ¾" shortie 351W swap headers that I bought from the company that bought Mac's remaining stock after Mac shut down (I found them selling all kinds of Mac Parts on eBay awhile back & asked them if that's what the situation was & they confirmed it.) The 351W headers do have a 1 piece mounting flange. Also, the flanges where they bolt to the H-pipe are NOT threaded [like the BBK's you mentioned], they actually have oval holes & they came with bolts & nuts to use instead of screw-in studs.
🔔😎 Good job! Well done video. Those sure look better than some of the headers pictures that I sent you. Smh. Quality has gone down from some of the manufacturers. BTW, I've seen 2 sets of those really beautiful china stainless headers that the full length mounting flange... From one end to the other overall, the holes were 1/4 inch short. China stuff. 🙄 Always good to see your new videos. Keep up the good work.
Personally, I wasn't too happy with mine.... always had to use a damn pry bar to get it to line up the bolt holes. They also blew gaskets pretty easy. I love their cat back though.
BTW, I had these on E7's and P heads. I now have BBK's on P heads, and with 90 degree Chevy plug wires, the BBK headers have better clearance than my MAC's did.
Whaaa? I didn't know anything happened to MAC! I installed those headers (ceramic coated) on my 91 LX, no problem. Mine have never leaked, but the ceramic is rusting in spots.
got a brand new set going on my 89Lx when i rebuild the trans. The long tubes have lived their life. over 25yrs on the car and they're done. going back to shorties and off road h pipe. just because i have them lying around. my 79 Cobra has had a set on it for 30yrs. thats how i coverted to dual exhaust.
I bought JBA back (late 90's) n the days, because friends had hard time line up the holes from MAC. especially bending over in a tight garage. It was a nightmare.
@@KASLCustoms Really. It'd be nice if someone still made a GT40P specific shorty header, but I guess it's not profitable when so few people are doing GT40P swaps these days. For now a 90 degree boot with heat shield on cylinder #7 and a modified side entry socket is the best answer. Also long tubes apparently have zero issues.
@@NGG1983 There are some cheapo sets listed on eBay that they CLAIM fit P-heads. Have no idea if they do. JBA does make P-headers for 1st Gen Mustangs & Southwest Speed (?) was making them for street rods (don't know if they still do).
I always regarded Mac as the cheapest will-do headers available. Their 351W swap headers were some of the better fitting ones they made. I always ground the slag out of the tubes where the flange is welded on before use. Every set I ever saw had alignment problems with the bolt holes on the heads, and if you used aluminum heads this created a serious cross thread potential. There is a tool called the “Chevy Exhaust Manifold Spreader” which greatly aided installation. In virtually every case these headers were installed with a set of header bolts with 3/8” heads, not socket heads.
Mac mufflers has a unique sound. The best sounding sbf exhaust I ever used. When you showed the GT40p with the GT40p stamping in the video it looks like 3 bars on the side, but P's are definitely 4. Was that lighting or what?
Saw your videos on the explorer intake and the gt40 heads not the p heads. I picked them up from a junk yard and think I might put them on my 94 5.0. I know that you probably don’t know too much about the 94-95 gt cars but I have a question about some some things. Have you ever used the calibrated maf censors I think I might use 24lb injectors on my car and then get the right maf for it. Just wondering if you knew if they worked well or not. Next how much power would you make with a stock 5.0 explorer intake, gt40 heads and with or without the 24lb injectors and maf. How much power would I make without a tune. I know the Fox and sn95 have different computers and so on but wondering if you would know about it or know someone who would. I bought the heads for $88 Canadian and have someone willing to pay 500 maybe more if I can work up the price. Looking at the parts I would need for the heads and intake swap I am wondering if I should just cash out you know? Thanks if you can help and really like the videos.
Thats a lot of questions but I will try and work my way through them. The MAF's are programmed specifically for the injectors you buy and yes they work well. The heads are good however a key component you will be missing it the intake manifold. In all honest, that is more of a choke off point than the stock heads. If you are doing all of this on a tight budget, You could sell your GT40 heads and buy a good intake and a decent throttle body. Don't worry about the tune or injectors until you get further down the road and buy heads etc.
@@KASLCustoms Oh I forgot to say but I got the explorer intake as well so I have heads and intake so have the heads and intake part of a the classic swap but don’t have a cam yet and probably will get one later but at that point I might need a tune. Yea I just wanted to ask if doing the the explorer heads and intake with the stock computer and maybe the maf and bigger injectors will even add much power without a tune. Oh I also have the throttle body from the explorer as well. Just kinda a hard decision since I put the heads up for sale just to see if there is demand and so on and already have a person willing to pay 700 for the heads.. not bad when I only payed 88 from a yard. Just haven’t decided yet
@@Macho_MTYou did mention the Explorer intake. Seen magazine articles back in the day that the "P" heads are worth at least 25HP (don't remember the claimed numbers for the standard GT40 heads) & the Explorer intake is worth at least 20.
@@foxfordcatguy2283 Yeah think I saw that article as well. As for the P vs non-P heads, the p makes a bit more because they have a smaller cc chamber there for more compression. On RUclips Richard Holdener has some great videos showing small block Ford modifications and the dyno charts he has lots of good videos. But yeah I kept the intake and plan on putting it on the car before summer maybe adjusting the timing as well.
Mac Headers were always my fav. YOU can pry them into place to get a bolt started its not rocket science. I hate the single flange type headers. just my 2 cents. BRING BACK MAC!!!!
I bought a MAC 3" Cat-back exhaust with the Flow Path mufflers and the 3" polished tips about 2 years ago, right when they were shutting down, but I didn't know that they were. They had already sold out of the 3" Pro Chambers. Darn it! I really wanted to use their Pro Chamber....heard good things about it.
Have a set of coated MAC equal length shorties on my 90 Vert now. I really like them…. Had a set of BBK back in the day and the MAC are far superior; just a PIA to get on
I thought I made a comment about my true 3" prochamber short Hpipe/Prochamber. It is for sale along with new BBK 1 3/4 Ceramic longtubes. Canada's gotta cost a fortune to ship to
I ran a set of Ford Motorsport ceramic coated headers on my first set up along with a Mac off road H pipe that i still have sitting in my attic collecting dust. was always happy with it and ease of install. good trip down memory lane
Recently got into a fox and had no idea what Mac headers were. Unfortunately it means I missed out on new Mac polished headers for $30 at an auction. I’m still kicking myself. Not to mention other things that went dirt cheap, drag rims,msd dist. Etc. sucks being underfunded and inexperienced.
My first headers, stut tower brace, and H-pipe were MAC. I totally remember looking through their catalog around 1995. If I looked hard enough, i might even have that catalog! Gotta love retro Speed parts! Awesome video!
🔔😎 You should have shown them the flange welds on my new big name company set I got in Nov. Everybody needs to grind down any bad welds. 👍 I plan to grind them and tig them if necessary.
If I remember correctly, when I ordered my pro chamber in 2003 , you could get cats in the down tubes or non cats . The down tubes was a separate piece , and they bolted to the pro chamber . If YT allowed I would send you a clip of Mac shorty with pro camber ( non cats ) and flowmaster .
As far as header bolts go, your gonna get header specific bolts that has a smaller 11mm head on them to fit around the fatter header tubes. That goes across the board regardless the brand of V8 engine. Plus I'm kinda like 50 Tussin as far as collecting them old parts. Plenty of guys my age(50years) are getting out of the 5.0 game and these old second hand parts are drying up. Me, I've been in the game since these cars were new and I'm not stopping!!
Okay, Mine are the MAC 90-8690 equal length and on P heads there is an issue on the passenger side with #4 cylinder and the spark plug. Now I"m hoping shorty plugs will help or else they will need to be peened. But getting those with full threads is not easy to find. All this on a 95 GT .....@@KASLCustoms
@@KASLCustoms Yeah thats what the guy who I bought it from told me, I got in 2021 I'm glad you make these videos man I love all this stuff I love learning about these cars and older products I didn't know about!
I still have a set of MAC 1.75" long tubes on my 93 Lightning. I'm not a big fan honestly. THe coating was very thin and they surface rusted badly even though the truck still has only 30k miles and is garaged. ThE individual flanges are a pain to line up.
Amazing video. I put that Mac catback on my 87 coupe in the mid 90s. Back in the day, the Mac kit had much nicer full chrome tailpipes vs. the Flowmaster option. Damn time flies.
Wow, thanks… seeing those prices makes me even more impressed I only paid $400 for the 3” pro chamber and longtubes and they are Brand New 😂 I’m a big MAC fan
Great video, for a great product. I've got MAC equal length shorties bolted to my 3 bars since 95. They've got well over 200k kms on them with 1 broken stud and 1 burnt gasket from bolt coming lose. Zero fitment issues, zero leaks!! Too bad they're out of business.
I did have the MAC headers I bought used from a junkyard for a weekend only because they were way off lining up. I took them back and bought BBK shorties. My BBK headers I bought back in the day seemed to be better quality than they make now.
I always loved MAC's products. I ran MAC pulleys, shorty headers, off-road X-pipe, and Flowpath catback on my old 87 LX; and all those parts are still on the car to this day. I also ran MAC's 3" catback on my old 04 GT as well.
I have MAC equal length headers, MAC prochamber, MAC cat back on my 90 GT. A pry bar is your friend getting those runner tubes lined up. Here in Nova Scotia we call them MAC DADDY'S ! LOL Actually, have the MAC strut tower brace and throttle body as well.
Yeah they legit gave you a lil more hp. Also when you install them you want to start the 2 outer bolts just like normal on any of them. Only it alloys the header to stretch out across the full length when prying it over so once you get the outer bolts started the others will line up. Amazing i remember this crap after 25 years lol. Keep up the great content bud youre one of my favs! 👍
I have a set of MAC mufflers on my Capri currently, they're coming off for a new exhaust in the spring, they do have a nice sound, just going to try something different. There is someone (or company) in the states that are building the Pro Camber, somehow the managed to get a hold of the original prints/specs and have started reproducing them, had read an article about just the other day, if I can find it I'll post it up. Great vid, love the history!
I know some company (think it was a motorcycle shop) bought Mac's remaining inventory when they shut down. I bought a set of Mac 1/¾" 351W shortie swap headers from them. Maybe they bought the designs as well.
My 86 gt has a set of Mac long tubes with power chamber off road h pipe and a flow path true fit cat back that I put on it about 20 years ago. I love that exhaust it sounds awesome, makes good power too, and i've never had any issues with leaks. I think it was only around a thousand bucks for the whole system at the time also while the similar BBK system was closer to 1500
I have a set on my 88 that I cannot wait to take off and scrap, both mine are like 1/2 inch off on the front header, I had to use a manifold spreader to get them back on, actually stripped a bolt on my E7 heads due to the misalignment, I was really freaking out when putting them on my trickflows lol. I will not sell them and hand off this problem to the next person. I really got punked when I bought them used...
To this day, I still have MAC rear lower control arms (Hotchkis knock offs), MAC strut tower brace, and the MAC cat back with the 3” tips. I absolutely love the cat back system. The adjustability is fantastic, and I can remove the tail pipes after the axle quickly for a meaner dumped exhaust note. I do have BBK products on my Mustang as well. Shorty headers, off road H pipe, under drive pulleys, throttlebody and spacer, CAI, Clutch quadrant, firewall adjuster, and caster camber plates. The only BBK products I haven’t had an issue with are the caster camber plates, and the quadrant, firewall adjuster. I’m still looking to find a MAC pro chamber. They sound so good!
I wanted a full MAC exhaust in the late 90's but everytime I went to Mustangs Unlimited (was local for me) they were always sold out. I ended up with Flowmaster 2 chambers and h-pipe. Never got the headers.
The other problem with these was that it put a lot of pressure on each port's bolt holes and the gaskets because they weren't collectively supported.......I remember the prybar action with these back in the day.
20 minutes with a grinder and that slag in the ports of the BBKs will be gone and you'll be left with a header with as smooth an entry as those MACs, and (bonus) because of the single flange design, they'll actually bolt up.....I've had MAC shorties (in the past) and currently have a set of 351w long tube swap headers with the same issue (not yet installed) that I got years ago back when they were the only thing in stock, I dread having to heat and beat them to get the holes to line up...IMHO BBKs are better in every way, if you take the time to address the ports...but everybody has an opinion, so good for you for loving the MACs, I respectfully disagree.
had Mac headers never had a problem and they had 1 and 3/4 shortys
👍👍👍
Long tube Mac's, with H pipe and 40 series Flowmasters with 3'' tips CAN NOT BE BEAT on sound.
👍👍👍
Heck it’s getting hard to find sbf parts for a mustang, everything is ls for a mustang.
It’s true
Just ran downstairs and checked. I have those!!!
Nice!
Awesome video buddy🙌🏼
Thanks brother!
I have a set of Mac Longtubes on my Capri that I got for Christmas in 1995. I love Mac headers!
Yeah buddy! That is awesome!!
Love the info videos. On a side note I will not be buying long tubes after listening to the podcast the other day. Thanks for the savings
Thanks buddy! Glad I could help 👍
I used to have 1 3/4 MAC unequal length shorty headers with the MAC produmps! Best sounding set up period!
Nice! I love the sound too!!
I remember getting the under drive pulley set from Mac,, they were a great company! Sad to see them out of business!! 😢😢😢😢great content!!
Me too! Thx buddy 🤙
I have a set of Mac 351w swap fox body long tubes that I bought in '95. They are still solid and work great!
Nice!
Mac did great products you stand correct
Agreed
I have the complete front to back MAC exhaust system on my 1994 GT convertible Mustang.. Still sounds awesome.
That’s deadly!
i still have a set of mac flow path mufflers on my 91 lx since the 90s and i love them .using mac equal length headres .with bbk no cats h pipe .i actualy took off the old 40 series flow masters and love the mac so much better ...i even gained 2 tenths on the quarter mile just from swpping out the mufflers test done in 1998 ...yes i own the 91 33 years bought her new
Congrats! Thats amazing
I used MAC Exhaust back in the day good stuff.
👊👊👊
Great video Brother! Honestly I miss Mac products! You have a great find.. .Hold on to them for sure!! 💯👊🏾
Thanks buddy! Yeah me too
What's good KASL, LOVE YOUR CHANNEL I have a brand new still in the box, 3 inch mac pro chamber for (LONG TUBE HEADERS)... I'M PRETTY SURE IT'S THE HOLY GRAIL😊.. might consider selling it.
Hey bud! Thanks so much. Wow that is awesome! Keep me posted!!
i use the flow path mufflers and i have loved them since 1998 they sound awesome and perform amazing and yes i bought 2 sets of mufflers i stll have a brand new set still in the boxes in my house garage
That’s awesome!
I still have a set of MAC equal length shortys on my 83 stang. They work awesome but didnt line up without prying.
Mac had the only Auto Transmission Longtube Headers; I put then on my LX in the late 00's!
I'm running the MAC equal length shorty headers to this day.
Very nice!
I saw a dyno test with Mac mufflers against all the popular brands and they came out on top, and loved how they sounded on my Mustang
Too cool!
I have a brand new set of 351W 1 7/8 jet hot coated shorties in the box. It took MAC over 9 months to get them to me. One day I'll find a project home for them.
Sweet!
I never saw Mac 1 ⅞" 351W shorties.🤔 I have a brand new set of their 1 ¾" 351W shorties.
Also used to see MAC and BBK products in the 90's
👍
I had a pair of short stainless mac headers on my 93 notch back with mac x-pipe with single stage flowmasters and it was the absolute best sounding exhaust ive ever had and dare say ever heard on a fox body.
Nice!
I still have Mac headers on my original owner 1995 GT40X headed ultra clean GT. I had no trouble fitting them and they are still Grey and clean.
My first H pipe and pulleys were MAC... purchased at MOPAC
Nice!
I have a complete Mac exhaust setup on my 1991 LX installed in 1993. Still leak free.
Also the underdrive pulleys and March ram air kit.
Thats awesome!
Even cooler!!!
Man I've been looking for a set for 3 years
Yeah they are getting hard to find...
I’ve had at least 5 different sets of Mac headers 20 years ago or more. I never had an alignment issue. The alignment issues with them usually were with using the stock bolts and those ridiculously large heads and built-in washers. The washers were usually the culprit for misalignment. Using smaller header bolts was always a win for me so I never bothered with factory bolts. Mac headers were great, especially if they were coated. I still have a 3” Power Chamber but it’s not being used. It may go back on when the stroker Cleveland goes in, but that’ll be later this year. Great video
Well said sir! Thanks for weighing in 👍
Would love a power chamber.
Me too bud!
Good video. I have a set of MAC equal length headers with X pipe I am going to try to use.
Thanks buddy! Right on!!
I got one of them sets on my stang. Yeah 240 bucks, and i did have a fitment issue with the last bolt hole on no 8 cylinder. Had to enlarge the hole to get the bolt in. Bought them back in 94 and still have them on thecar today. Had one of their no cats H pipe that rusted within a year. That was disappointing. Thanks for the memories.
MAC never impressed me with their quality but to their credit, they seemed to make a header for every conceivable combination. Example, TFS high port heads on a 351 with a Lakewood bellhousing, big primaries and alternate bolt pattern. Okay, I'm not sure they specifically offered headers for exactly that, but they seemed to really try to cater to everyone. I never liked the individual flange design, but in retrospect it might have been a good idea. It seems like they would flex more and seal better like the factory headers that are the same way. You never had bolts backing out of those.
Yup well said my friend
Hey guy, I always installed a straight metal bar under the tubes after lining tunbes up.
👌👌👌
I always used a pry bar to push the tube over and then start the bolt. Iv got lots of experience with mac headers and theyre my favorite.
LOL - thats awesome 👊
Full Mac exhaust on my car. Wish I could find a prochamber
Yeah bud, thats the holy grail!!
Also funny, when the single flange gets warped you have to cut them..😏
This is true
@@KASLCustoms when I had to reinstall my headers like a yr n a half ago only way I was able to get the last 2 bolts in was a big pry bar and a prayer, the relief after wrestling with it for like an hr was so sweet lol.
@@KASLCustoms Won't help with these specific headers but try using studs for heads. They have the small non threaded part that locates manifold holes nicely and use as much thread as possible for less point load stress.
Will do thank you!
🤣🤣👊👊
1) Mac did make specific GT40P headers, 1 set for Foxes & a separate set specific for the '94-'95 Mustang. I have a brand new set of Mac Fox "P" headers I bought not long before they shut down.
2) I also have a brand new set of Mac 1 ¾" shortie 351W swap headers that I bought from the company that bought Mac's remaining stock after Mac shut down (I found them selling all kinds of Mac Parts on eBay awhile back & asked them if that's what the situation was & they confirmed it.) The 351W headers do have a 1 piece mounting flange. Also, the flanges where they bolt to the H-pipe are NOT threaded [like the BBK's you mentioned], they actually have oval holes & they came with bolts & nuts to use instead of screw-in studs.
🔔😎
Good job! Well done video.
Those sure look better than some of the headers pictures that I sent you. Smh.
Quality has gone down from some of the manufacturers.
BTW, I've seen 2 sets of those really beautiful china stainless headers that the full length mounting flange... From one end to the other overall, the holes were 1/4 inch short.
China stuff. 🙄
Always good to see your new videos. Keep up the good work.
Thanks buddy!
Personally, I wasn't too happy with mine.... always had to use a damn pry bar to get it to line up the bolt holes. They also blew gaskets pretty easy. I love their cat back though.
BTW, I had these on E7's and P heads. I now have BBK's on P heads, and with 90 degree Chevy plug wires, the BBK headers have better clearance than my MAC's did.
@@89G ive been running the bbks on my P heads for several years set up just like yours and I haven't had any issues yet.
@@BruceLee-xn3nn I have the same setup on both of mine, and it works well.
Yeah it was somewhat common for these sadly… glad the BBK’s are working though bud 👍
@@KASLCustoms my BBK's are about 7 years old though... maybe the quality has gone bad since then.
Mac exhaust is the best exhaust ever! Matter of fact mac exhaust is god of mustang exhaust. And had the best sound ever!
I still have a set of equal length shorties with x-pipe to the full exhaust on my SN95...
Nice!
Cool stuff man. My buddy had a set with the pro chamber H pipe and Flowmaster and it sounded wicked.
Thx bud!
Whaaa? I didn't know anything happened to MAC! I installed those headers (ceramic coated) on my 91 LX, no problem. Mine have never leaked, but the ceramic is rusting in spots.
got a brand new set going on my 89Lx when i rebuild the trans. The long tubes have lived their life. over 25yrs on the car and they're done. going back to shorties and off road h pipe. just because i have them lying around. my 79 Cobra has had a set on it for 30yrs. thats how i coverted to dual exhaust.
Right on!
I had a set of 3” exhaust from Mac with mufflers I think
👌👌👌
I bought JBA back (late 90's) n the days, because friends had hard time line up the holes from MAC. especially bending over in a tight garage. It was a nightmare.
JBA’s we’re really nice 👌
I have a set of MAC long tubes and a pair of those flow path mufflers in my parts stash
You’re hanging onto old school gold 😉
MAC used to make GT40P specific headers, and the ones you've got there might not be them.
Oh really? I didn’t know that?
@@KASLCustoms Really. It'd be nice if someone still made a GT40P specific shorty header, but I guess it's not profitable when so few people are doing GT40P swaps these days. For now a 90 degree boot with heat shield on cylinder #7 and a modified side entry socket is the best answer. Also long tubes apparently have zero issues.
Yup I agree
@@NGG1983
There are some cheapo sets listed on eBay that they CLAIM fit P-heads. Have no idea if they do.
JBA does make P-headers for 1st Gen Mustangs & Southwest Speed (?) was making them for street rods (don't know if they still do).
Love seeing vintage brochures from back in the day, awesome video Gary 🤙👌
Thanks buddy! Yes I'm glad I hung onto them
Awesome!!!! I had mac shorties, a Mac off road h pipe and the mufflers back in the day on my 1988 mustang gt in high school..good old days!
Too cool!!!
I always regarded Mac as the cheapest will-do headers available. Their 351W swap headers were some of the better fitting ones they made. I always ground the slag out of the tubes where the flange is welded on before use. Every set I ever saw had alignment problems with the bolt holes on the heads, and if you used aluminum heads this created a serious cross thread potential. There is a tool called the “Chevy Exhaust Manifold Spreader” which greatly aided installation. In virtually every case these headers were installed with a set of header bolts with 3/8” heads, not socket heads.
Good info, thanks for sharing sir!
Definitely fix any welds with a die grinder. 👍😎
Still got Mac headers and mufflers in my fox sound amazing Amd the headers fit my promaxx heads perfectly
Nice!
Didn't see the rearend girdle in that brochure🤔 picked up one of them back in the 90's when they first came out, still on my car to this day
Thats awesome!
Mac mufflers has a unique sound. The best sounding sbf exhaust I ever used.
When you showed the GT40p with the GT40p stamping in the video it looks like 3 bars on the side, but P's are definitely 4. Was that lighting or what?
Agreed! Yes sorry I noticed that as well, it is most definitely a lighting issue.
My best friend has a set of MAC headers bolted up to TFTW heads on his 89 LX Sport and I have JBA headers on Dart Senior heads in my 89 LX Sport.
Nice!
Saw your videos on the explorer intake and the gt40 heads not the p heads. I picked them up from a junk yard and think I might put them on my 94 5.0. I know that you probably don’t know too much about the 94-95 gt cars but I have a question about some some things. Have you ever used the calibrated maf censors I think I might use 24lb injectors on my car and then get the right maf for it. Just wondering if you knew if they worked well or not. Next how much power would you make with a stock 5.0 explorer intake, gt40 heads and with or without the 24lb injectors and maf. How much power would I make without a tune. I know the Fox and sn95 have different computers and so on but wondering if you would know about it or know someone who would. I bought the heads for $88 Canadian and have someone willing to pay 500 maybe more if I can work up the price. Looking at the parts I would need for the heads and intake swap I am wondering if I should just cash out you know? Thanks if you can help and really like the videos.
Thats a lot of questions but I will try and work my way through them. The MAF's are programmed specifically for the injectors you buy and yes they work well. The heads are good however a key component you will be missing it the intake manifold. In all honest, that is more of a choke off point than the stock heads. If you are doing all of this on a tight budget, You could sell your GT40 heads and buy a good intake and a decent throttle body. Don't worry about the tune or injectors until you get further down the road and buy heads etc.
@@KASLCustoms Oh I forgot to say but I got the explorer intake as well so I have heads and intake so have the heads and intake part of a the classic swap but don’t have a cam yet and probably will get one later but at that point I might need a tune. Yea I just wanted to ask if doing the the explorer heads and intake with the stock computer and maybe the maf and bigger injectors will even add much power without a tune. Oh I also have the throttle body from the explorer as well. Just kinda a hard decision since I put the heads up for sale just to see if there is demand and so on and already have a person willing to pay 700 for the heads.. not bad when I only payed 88 from a yard. Just haven’t decided yet
No worries buddy. I hope my info helped 👍
@@Macho_MTYou did mention the Explorer intake.
Seen magazine articles back in the day that the "P" heads are worth at least 25HP (don't remember the claimed numbers for the standard GT40 heads) & the Explorer intake is worth at least 20.
@@foxfordcatguy2283 Yeah think I saw that article as well. As for the P vs non-P heads, the p makes a bit more because they have a smaller cc chamber there for more compression. On RUclips Richard Holdener has some great videos showing small block Ford modifications and the dyno charts he has lots of good videos. But yeah I kept the intake and plan on putting it on the car before summer maybe adjusting the timing as well.
I recently came across an old-school Mac exhaust, and I cannot be happier. I love them. Definitely has a unique sound.
👌👌👌
Mac Headers were always my fav. YOU can pry them into place to get a bolt started its not rocket science. I hate the single flange type headers. just my 2 cents. BRING BACK MAC!!!!
I bought a MAC 3" Cat-back exhaust with the Flow Path mufflers and the 3" polished tips about 2 years ago, right when they were shutting down, but I didn't know that they were.
They had already sold out of the 3" Pro Chambers.
Darn it!
I really wanted to use their Pro Chamber....heard good things about it.
Yeah its a sad course of events...
Gotta know what you're doing when using those P heads!
This video definitely clears up what's in play with some of those headaches.
They are actually my buddy's and he is selling them. Thanks buddy
I got the mac windage tray, it works well and the beauty of it is it works with stock foxbody oil pan
Nice buddy 👌👌
Have a set of coated MAC equal length shorties on my 90 Vert now. I really like them…. Had a set of BBK back in the day and the MAC are far superior; just a PIA to get on
Nice buddy! Yes I agree
I thought I made a comment about my true 3" prochamber short Hpipe/Prochamber. It is for sale along with new BBK 1 3/4 Ceramic longtubes. Canada's gotta cost a fortune to ship to
Yeah its nasty!
I ran a set of Ford Motorsport ceramic coated headers on my first set up along with a Mac off road H pipe that i still have sitting in my attic collecting dust. was always happy with it and ease of install. good trip down memory lane
Nice! thanks for sharing bud!!
MAC was a lot better than BBK in my opinion I've had both has better fitment
👍
Don't heat and bend anything!! Just drill the hole larger in that one tube!!
I guess there is that as a option as well…
Recently got into a fox and had no idea what Mac headers were. Unfortunately it means I missed out on new Mac polished headers for $30 at an auction. I’m still kicking myself. Not to mention other things that went dirt cheap, drag rims,msd dist. Etc. sucks being underfunded and inexperienced.
LOL its true but live and learn bud 👍
Karma will shine again 👍😎
My first headers, stut tower brace, and H-pipe were MAC. I totally remember looking through their catalog around 1995. If I looked hard enough, i might even have that catalog! Gotta love retro Speed parts! Awesome video!
Thx buddy! Yep same here 👊
🔔😎
You should have shown them the flange welds on my new big name company set I got in Nov.
Everybody needs to grind down any bad welds. 👍
I plan to grind them and tig them if necessary.
Oh wow - not much better?
@@KASLCustoms emailed you the pics Feb 16 and you replied. 🤔
One set of 5.0
and 2 sets SBC
If I remember correctly, when I ordered my pro chamber in 2003 , you could get cats in the down tubes or non cats . The down tubes was a separate piece , and they bolted to the pro chamber .
If YT allowed I would send you a clip of Mac shorty with pro camber ( non cats ) and flowmaster .
Oh wow I didn't know that! Thats super cool!!
Anyone tried to put spacers between heads and headers for spark plug clearance or used shorter spark plugs
As far as header bolts go, your gonna get header specific bolts that has a smaller 11mm head on them to fit around the fatter header tubes. That goes across the board regardless the brand of V8 engine. Plus I'm kinda like 50 Tussin as far as collecting them old parts. Plenty of guys my age(50years) are getting out of the 5.0 game and these old second hand parts are drying up. Me, I've been in the game since these cars were new and I'm not stopping!!
Thanks, I did mention in my video that the bolts I was using were just for demonstration purposes. Did you catch that part?
@@KASLCustoms must have flew over my head. Was multitasking (studying).
What plugs did you have in the P heads and how did the passenger side work out?
I have never had the p's on a car. they are just explorer take offs
Okay, Mine are the MAC 90-8690 equal length and on P heads there is an issue on the passenger side with #4 cylinder and the spark plug. Now I"m hoping shorty plugs will help or else they will need to be peened. But getting those with full threads is not easy to find. All this on a 95 GT .....@@KASLCustoms
Mac was always better than BBK
They definitely seemed to put more time and care into their products thats for sure.
I bought my car that has a MAC pro chamber mid pipe on it
That's an awesome piece of history!
@@KASLCustoms Yeah thats what the guy who I bought it from told me, I got in 2021 I'm glad you make these videos man I love all this stuff I love learning about these cars and older products I didn't know about!
Too cool! Thx buddy!!
I got them on my 86 with matching h-pipe. Got them cheap off Craigslist. I think a shade over 200 bucks
Good find!
Nice score! Looks like fitment is pretty good to me. You’re absolutely right about the BBK welds. I smoothed mine out. 👊😎✌️
yeah, the Q&A has really gone for a 💩
I still have a set of MAC 1.75" long tubes on my 93 Lightning. I'm not a big fan honestly. THe coating was very thin and they surface rusted badly even though the truck still has only 30k miles and is garaged. ThE individual flanges are a pain to line up.
Amazing video. I put that Mac catback on my 87 coupe in the mid 90s. Back in the day, the Mac kit had much nicer full chrome tailpipes vs. the Flowmaster option. Damn time flies.
Thx buddy! 👊
Wow, thanks… seeing those prices makes me even more impressed I only paid $400 for the 3” pro chamber and longtubes and they are Brand New 😂 I’m a big MAC fan
Yessir 👊
Great video, for a great product.
I've got MAC equal length shorties bolted to my 3 bars since 95. They've got well over 200k kms on them with 1 broken stud and 1 burnt gasket from bolt coming lose. Zero fitment issues, zero leaks!!
Too bad they're out of business.
Thx buddy. I agree 👊
I did have the MAC headers I bought used from a junkyard for a weekend only because they were way off lining up. I took them back and bought BBK shorties. My BBK headers I bought back in the day seemed to be better quality than they make now.
Not quite so "exhausting" video on headers...shorty at that! HAHA!
LOL!!
I always loved MAC's products. I ran MAC pulleys, shorty headers, off-road X-pipe, and Flowpath catback on my old 87 LX; and all those parts are still on the car to this day. I also ran MAC's 3" catback on my old 04 GT as well.
Thats awesome buddy!
I have MAC equal length headers, MAC prochamber, MAC cat back on my 90 GT.
A pry bar is your friend getting those runner tubes lined up.
Here in Nova Scotia we call them MAC DADDY'S ! LOL
Actually, have the MAC strut tower brace and throttle body as well.
Do the bbk headers fit the gt40p heads?
Yes but you run into the same serviceability issues
You actually did gain more hp from mac over flowmaster too
Interesting. I know they say you would but seeing it on a dyno sheet with you own eyes would be pretty cool
Yeah they legit gave you a lil more hp. Also when you install them you want to start the 2 outer bolts just like normal on any of them. Only it alloys the header to stretch out across the full length when prying it over so once you get the outer bolts started the others will line up. Amazing i remember this crap after 25 years lol. Keep up the great content bud youre one of my favs! 👍
That’s good thinking! Hahahaha I love it. My hard drive is getting full to my friend 😂👊
I have a set of MAC mufflers on my Capri currently, they're coming off for a new exhaust in the spring, they do have a nice sound, just going to try something different. There is someone (or company) in the states that are building the Pro Camber, somehow the managed to get a hold of the original prints/specs and have started reproducing them, had read an article about just the other day, if I can find it I'll post it up. Great vid, love the history!
Thx buddy! Oh wow I didn’t know that. Please share if possible 🙏
I know some company (think it was a motorcycle shop) bought Mac's remaining inventory when they shut down. I bought a set of Mac 1/¾" 351W shortie swap headers from them. Maybe they bought the designs as well.
My 86 gt has a set of Mac long tubes with power chamber off road h pipe and a flow path true fit cat back that I put on it about 20 years ago. I love that exhaust it sounds awesome, makes good power too, and i've never had any issues with leaks. I think it was only around a thousand bucks for the whole system at the time also while the similar BBK system was closer to 1500
Dude that is awesome! I too love the sound of them!!
I have a set on my 88 that I cannot wait to take off and scrap, both mine are like 1/2 inch off on the front header, I had to use a manifold spreader to get them back on, actually stripped a bolt on my E7 heads due to the misalignment, I was really freaking out when putting them on my trickflows lol. I will not sell them and hand off this problem to the next person. I really got punked when I bought them used...
How did I never hear about this manufacturer?
I thought you had a set of BBK in the box. Excellent episode and history lesson
Thx buddy!!
What the hell, sold a set of these last year for like $100 lol. But I do have Mac equal length headers on my 5.0
Nice!
To this day, I still have MAC rear lower control arms (Hotchkis knock offs), MAC strut tower brace, and the MAC cat back with the 3” tips. I absolutely love the cat back system. The adjustability is fantastic, and I can remove the tail pipes after the axle quickly for a meaner dumped exhaust note.
I do have BBK products on my Mustang as well. Shorty headers, off road H pipe, under drive pulleys, throttlebody and spacer, CAI, Clutch quadrant, firewall adjuster,
and caster camber plates. The only BBK products I haven’t had an issue with are the caster camber plates, and the quadrant, firewall adjuster. I’m still looking to find a MAC pro chamber. They sound so good!
I have a set of mac shortys (stainless). What are they worth to sell? Thx
Nice! Honestly I am not sure?
Couldn't tell you how many hours I've wasted over the years prying those headers to get to align. Throw them in the trash
I wanted a full MAC exhaust in the late 90's but everytime I went to Mustangs Unlimited (was local for me) they were always sold out. I ended up with Flowmaster 2 chambers and h-pipe. Never got the headers.
Too bad. They were definitely popular
The other problem with these was that it put a lot of pressure on each port's bolt holes and the gaskets because they weren't collectively supported.......I remember the prybar action with these back in the day.
😂👊
20 minutes with a grinder and that slag in the ports of the BBKs will be gone and you'll be left with a header with as smooth an entry as those MACs, and (bonus) because of the single flange design, they'll actually bolt up.....I've had MAC shorties (in the past) and currently have a set of 351w long tube swap headers with the same issue (not yet installed) that I got years ago back when they were the only thing in stock, I dread having to heat and beat them to get the holes to line up...IMHO BBKs are better in every way, if you take the time to address the ports...but everybody has an opinion, so good for you for loving the MACs, I respectfully disagree.
Pain in the a$$ to install