ok. I'm about to drop in my motor. I've hooked up everything, set the headers in place, pianted my engine bay before that, and got all my parts and tools handy. but I was thinking..... where do i tap into for vacuum? I have a 1978 350 with a performer RPM 7101 manifold, is there any provision for it on the manifold? also, there's a little round unit that says rochester controls on it with like 4 tubes coming out. these are for vacuum.... what the hell do you mount this thing on? also, where do all the tubes go? I can make out some of the labels... one says carb bowl, but that's the only one i can read. what about the others?

 

isnt there a fitting between the dist. and carb?

 

I'm running an edelbrock 600 cfm carb and a GM performance HEI distributor with vacuum advance. I need to figure out where to hook those to... Also, my shift modulator on my TH350 needs a vacuum source too.

 

....dist. gets hooked to port vaccum.......i.e. not full vac.(on carb)

 

go to library an look at a chilton, or other auto service books and look at pics, vac. diagrams etc.. im not sure all your trying to hook up....

 

On your intake there should be a threaded NPT hole behind where the carb sits. between the carb and the distributor. run a fitting and put your brakes there.

On the carb itself, there are 4 vacuum nipples. Starting in back, thats a generic 1/4" NPT. On the front of the carb, Edelbrock logo side:

Big center one: PCV hookup
Lower right of PCV: Full-time vacuum port
Upper Left of PCV: Ported vacuum, distributor goes here

 

I'm running breathers. do I plug the PCV hole? also, where does the A/C plug into, and where do I plug in the vaccum modulator from the TH350? does that go on full vacuum or can it go on somewhere else? the way I'm understanding it is this:

manifold NPT to big fitting on back of carb.

distributtor is upper left

??? on lower right

??? on PCV


I still need to hook up:
vaccum modulator on TH350 tranny
A/C

thanks for the help guys!

 

what sizes are the TH350 modulator vacuum and the a/c?

 

modulator fitting is tiny. like, much smaller than the NPT fitting on the back of my carb. the A/C, I don't know... which A/C part would have the vacuum fitting? I'm not entirely sure it has to be hooked up to vacuum... but every other car I've ever worked on did, my best friend's rustang does, so I assume it has an A/C hook-up.

 

also, is the vacuum fitting on the back of the manifold about 1/2" in diameter? or is it smaller?

 

The modulator fitting might be able to be plugged into the full time vacuum port on the front of the carb.

AS for the manifold NPT, 1/2" sounds right, its been a while since i bought the fitting for it.

Cant say about the A/C....my car doesnt Have A/C.

 

ok, the distributor hooks up on the port vac side (left) and the full vacuum is on the left. I found the original tree, it's a canister with 4 nipples in a line from top to bottom, maybe i can use that. in order from top to bottom, it says this:

around the top of the canister: rochester Products control vac

then from top to bottom:

PCV
carb bowl
can/TVS

what's that mean? I have pics of everything; i just took them last night so if you want to see them i can send them. I think the way it works is I hook the full vac nipple to the very top nipple on the tree, I plug the PCV (I'm running breather filters on each valve cover) I plug in the carb bowl nipple into the carb nipple on the left side of my edelbrock, and the can/tvs goes to the brake booster. the brake booster has a hose coming out of it with a little round canister at the end of it. what is that canister for? another thought: originally, 82's and some 83's had TH200c trannies; these were electronically modulated. since I'm not using the original tranny, I'm using a TH350, I need to source vacuum. I'm NOT using the PCV stuff, since I'm eliminating the computer. now: can I use the pcv line to supply a source for the TH350's modulator? pcv is full vacuum... the TH350 would need full vacuum..... so couldn't i just use the PCV that way? thanks for the help. (where can i throw some pics up real quick for some last second hosting?)

 

just about figured out how it all hooks up. anyone know what A/C component needs the vacuum hookup? and which nipple on the firewall-mounted storage canister do i use to hook it up?