For a street vehicle, always run manifold vacuum to the vacuum advance. When you run ported vacuum to the vacuum advance, you don't have any vacuum advance when the throttle blades are fully closed. By not having enough advance at idle, the engine will not be happy at an idle, it will be very difficult to tune, and you'll likely end up turning up the idle set screw to get it to idle. When you do that, the carb will run on the transfer slot, and then the engine will consume a lot more fuel at idle. The late timing of the spark will cause more of the fuel to burn in the exhaust port, which will make the engine run hot. Also, the higher idle will cause the engine to constantly pull on the converter when idling in gear.
Yes, there is a lot of argument about it since many cars came with ported vacuum as part of an emissions scheme.The simple answer is that ported vacuum gives zero vaccum advance at idle, and a well tuned street engine will have vacuum advance at idle. The only way to get that is with manifold vacuum.
No, that’s the point. You don’t run advance at idle. That’s why you set initial timing at idle then tune your vacuum or mechanical advance with springs etc. You’re handing out bad advice. 😂
Yeah you'll get a better idle but you'll lose all that advance when you step on it. Vs a ported hookup will give you that advance. Manifold vacuum is good for aggressive cams that need that timing not a mild street build. Don't run manifold on a stock or mild engine@@pjnelson8971
@@4rdF1HunnyYES! You are correct! The chevy guys don't run enough initial timing for their engine to run smooth so they use the vacuum can to fool the engine into thinking it has more initial than it really does. Then they don't have enough timing at cruise to get good throttle response and fuel mileage!
Similar situation here Reroute of my pcv helped Thanks for the heads up on the transmission line port Mine too is blocked Afterwork im gonna do what u did with that port I appreciate ya posting
Thanks man for the video. I was trying to confirm where the transmission vaccuum line went. The truck i bought had the trans vaccuum and the brake booster tied in together coming off the manifold.
My 305 only has the pcv connected to carb,trans modulator and distributor advance ran to manifold vacuum port should i redo them the way you did it? Mines not shifting out of 1st gear or idling under load
For a street vehicle, always run manifold vacuum to the vacuum advance.
When you run ported vacuum to the vacuum advance, you don't have any vacuum advance when the throttle blades are fully closed. By not having enough advance at idle, the engine will not be happy at an idle, it will be very difficult to tune, and you'll likely end up turning up the idle set screw to get it to idle.
When you do that, the carb will run on the transfer slot, and then the engine will consume a lot more fuel at idle. The late timing of the spark will cause more of the fuel to burn in the exhaust port, which will make the engine run hot. Also, the higher idle will cause the engine to constantly pull on the converter when idling in gear.
I’ve read otherwise??
Yes, there is a lot of argument about it since many cars came with ported vacuum as part of an emissions scheme.The simple answer is that ported vacuum gives zero vaccum advance at idle, and a well tuned street engine will have vacuum advance at idle. The only way to get that is with manifold vacuum.
No, that’s the point. You don’t run advance at idle. That’s why you set initial timing at idle then tune your vacuum or mechanical advance with springs etc.
You’re handing out bad advice. 😂
Yeah you'll get a better idle but you'll lose all that advance when you step on it. Vs a ported hookup will give you that advance. Manifold vacuum is good for aggressive cams that need that timing not a mild street build. Don't run manifold on a stock or mild engine@@pjnelson8971
@@4rdF1HunnyYES! You are correct! The chevy guys don't run enough initial timing for their engine to run smooth so they use the vacuum can to fool the engine into thinking it has more initial than it really does. Then they don't have enough timing at cruise to get good throttle response and fuel mileage!
Congratulations! You are probably the only chevy guy who actually has his distributor set up with the correct vacuum port. (Ported vacuum) 🥳
Similar situation here
Reroute of my pcv helped
Thanks for the heads up on the transmission line port
Mine too is blocked
Afterwork im gonna do what u did with that port
I appreciate ya posting
I have never seen vacuum modulator to ported vacuum on the carburetor, I think is always better to run transmission modulator to manifold vaccum.
Looks like a good ground to the vacuum modulator PCV intake regulator advance timing Transfunctioning Continuator!!!😂😂😂
Thanks man for the video. I was trying to confirm where the transmission vaccuum line went. The truck i bought had the trans vaccuum and the brake booster tied in together coming off the manifold.
Yours was correct!
‼️the valve cover bolts u have, the tops will pop off and on, pop them off and put them back on straight, it will make it look allot cleaner‼️
What about that upper vacuum hose by the carb air intake? I have one that goes nowhere on the 68
Galaxie stock 2-barrel carb 390
Break booster?
TH350/TH400 gets Full manifold vacuun. Not ported
This here 👆🏼
My 305 only has the pcv connected to carb,trans modulator and distributor advance ran to manifold vacuum port should i redo them the way you did it? Mines not shifting out of 1st gear or idling under load
Would you advise replacing my quadrajet with an Edelbrock?
I've called them qaudrajunk for 36 years for a reason. Just my opinion though.
The Edelbrock is very simple and reliable, it's like a quadrajet for dumbasses.
Qjet tuned properly are fine, however an Edelbrock avs2 is a great carb.
You used fuel line for the vacuume line you should use vacuume line cause fuel line will collapse with vacuume
What about the small vacume at rear of carb?
The pcv should go to the breather that 3/8 should go to the brake booster or capped
My distributor doesn’t have vacuum advance it has this 3 prong connection no vaccum advance why is that?
Except the pcv line it's normally a fuel/pcv line but the others should be vaccume line
Pcv valve... You understand the v in pcv stands for valve.. pressure control valve valve is what you're saying.
Nice
Is it shifting
Yes
What are those !!!!! Fingernails
Monster claws
It ain't got no ⛽.....
whats going to brake booster?
Brake booster port is behind the carburetor
Mine - brake booster on a 75 ford is routed into the intake manifold
Hose clamps?
Never in my life.