i have a 78 cutlass, with a 68 350 rocket in it, has a holly 600 4 bbl carb, i'm having trouble with the vaccum lines, is there anyone who knows how to hook them up or is there a diagram i can get to figure it out? thanks!
help please?
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There is brakes, heater, cruise control, pcv valve, egr valve, distributor, trans, and maybe some other things. Most can be connected through ports in the intake manifold, but some need to be on the carb.
Oh, OK thanks for clarifying that for me, i forgot to mention that its a marine carb on it, i don't know if that makes a difference or not for hooking up the vacuum lines... I'm not concerned about cruise control to much (on the count of i wont be using it), but the others i am.. i just don't know which valves to hook the lines up to,
There should be a vacuum line on the main metering block that is above or below the mixture screw. That is the ported vacuum source, and it is used to drive the distributor's vacuum advance can. The power brake booster is driven off manifold vacuum and it will go to a fitting that is about 5/16 to 3/8 in diameter, and there should be a small filter in line with it as well. Now for the HVAC vents, it gets a little more tricky. There should be a purple line (on mine at least) that runs to a vacuum reserve canister. From the canister it should go to a check valve and then proceed to be driven off a manifold vacuum source. Manifold vacuum comes either from the base of the carburetor or a fitting on the intake manifold itself. (Ported vacuum comes from above the throttle blades). If you have a TH 350 automatic transmission, you will also have what is called a vacuum modulator. This performs the load sensing function that is done on later transmissions with a TV cable. I believe it uses manifold vacuum as well, but I am not 100% sure. If you do not have a manifold vacuum port, you may have to remove a pipe plug on the intake manifold and screw one in. Anyhow, that is all I can think of. I did this from memory, so I may have missed a detail or two, but it should be pretty much correct. After all, these connections are fairly generic on most old cars and if you have seen one, you've seen em all. After all, this is a G body, not something wacky like a Citroen GS Birotor. :lol:
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I'd get another carb to start with... 600 cfm isn't enough for a 350.
4bbl cars came from the factory with a 750.
The motor will run out of breath far short of what it's capable of.
4bbl cars came from the factory with a 750.
The motor will run out of breath far short of what it's capable of.
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