Th350 vacuum line hook up

How much vacuum to shift a TH350?

I just instaled a new th350. Guy at the tranny shop said it needs 16in. of vac to shift properly. my old tranny vacuum line ran to the carb. He said thats not good enough, need to run it to the distributer. I have msd dist no vac advance. so he says run it to the intake. I say okay.

What are the specs of a TH350 transmission?

Specs- 350 engine, Edelbrock Performer EPS manifold, Holley 4160, TH350 trans (rebuilt w/shift kit), 3.73 posi. I stopped at the transmission place that rebuilt my transmission about a year ago.

Do you hook your distributor up to ported or full vacuum?

My distributor is hooked up to full vacuum, not ported. You will not get good performance if you distributor is on the ported or timed vacuum source. It has to sense manifold vacuum. You cannot use the distributor line, because that is ported vacuum Click to expand... My distributor is hooked up to full vacuum, not ported.

Where to connect vacuum line to power booster?

They looked at it and said the vacuum line should be connected to a vacuum port directly on the manifold, ie. the same one that the brake power booster is connected to. They said insufficient vacuum would be causing the late shifts I described.

How do you adjust the vacuum modulator on a GM TH350?

A minimum of 12″ Hg engine vacuum is required for proper operation. You can adjust the modulator with a small screwdriver. Turn the adjustment screw clockwise to raise shift points and counter-clockwise to lower shift points. B&M Vacuum Modulator for GM TH350/TH400 Automatic Transmissions ~ Part # 20234 on Amazon

How do you raise the shift points on a GM TH350?

Turn the adjustment screw clockwise to raise shift points and counter-clockwise to lower shift points. B&M Vacuum Modulator for GM TH350/TH400 Automatic Transmissions ~ Part # 20234 on Amazon

How much vacuum needed to shift properly?

Guy at the tranny shop said it needs 16in. of vac to shift properly. my old tranny vacuum line ran to the carb. He said thats not good enough, need to run it to the distributer. I have msd dist no vac advance. so he says run it to the intake. I say okay.

What happens if there is no vacuum in transmission?

Without vacuum to the tranny, it will shift late, thinking it is full throttle. If it doesnt shift by e.g. 5000 rpm, that sounds like trouble. :- ( I think that B&M and others make a vacuum modulator for the transmission to accomodate a hot-cam engine which produces much less vacuum.

“Ported” vacuum allows little or no vacuum to the distributor at idle. “Manifold” vacuum allows actual manifold vacuum to the distributor at all times. Does your engine require additional timing advance at idle in order to idle properly?

What should the vacuum advance be on a distributor?

Where is the power brake booster connected to the vacuum line?

The tranny vacuum line and the power brake booster will both connect to it. Your car doesnt have an EGR valve, do you mean PCV valve? If so, there should be a large vacuum port somewhere on the baseplate of the carb.

How does a vacuum booster work?

­ ­The vacuum booster is a metal canister that contains a clever valve and a diaphragm. A rod going through the center of the canister connects to the master cylinders piston on one side and to the pedal linkage on the other.

Does the power brake booster line go to the CARB?

you should probably hook your transmissions vacuum line, and your power brake booster line to a vacuum fitting on the intake manifold. Yes, distributer goes to carb. TH350s dont have electrical detent switches..Are you sure its not a TH400?

Where do you hook up the vacuum advance line?

There are differning opinions on where to hook up the vacuum advance line. There are two possible vacuum ports on the carb. One is a ported vacuum source and the other is an unported vacuum source. Try both and use the one that makes the car run the best.