Please someone help me out. 68 cutlass...4bbl manifold. Put on quadrajet and curious which vacuum is which. Think I only need to run for distributor advance, line to trans, brake booster and pcv valve. Anyone tell me which ports are better for which????

 

I am assuming from your picture that you bought a new carb from Summit.
If so, it should come with a diagram of the connections, which may be slightly different from the original (for instance, it has a right angle fuel inlet), so it would not be helpful to you for me to guess about them.

If you are installing an original carb, I and others can help you , but you could also just look in the Chassis Service Manual.

- Eric

 

Vac. Advance to the port on the DRIVERS side front of the carb...middle of the Float Bowl Casting ( Main Body ). PCV to the BIG port at the base in front center of carb. I suggest capping the rest in the carb and put a fitting in the intake for Trans Vac Modulator and Brake booster...two seperate fittings not all one ( sorry ) ...Hope this helps.

Danny

 

I agree with Danny. Your generic "Chevy-style" Qjet has ports that may or may not match those on your original carb. Olds always used a port in one of the rear intake runners to provide vacuum to the power brakes. The trans modulator just needs manifold vacuum - could be the carb port or an intake runner port. Use a vacuum gauge to verify which port does which on the carb once the engine is running.