Were does vacuum advance line hook up on carburator for a 1970 400 pontiac gto?
Vacuum advance for 1970 was connected thru a solenoid and shut off until top gear using the transmission switch to allow or deny vacuum to the advance in the factory setup. The debate is split among car guys as to which carb hookup to use ported or manifold attachment on cars without egr and pollution controls. The consensus seems to be that you set your timing and idle with the line plugged off on carb and then try each hook up and see what works best for you. I have a 1973 400 in my GTO and all the pollution gear is removed. I recently fixed my advance and so far have found manifold or below the butterfly to work best for me but, as I stated some swear by the ported or above the butterfly hookup and a pretty good arguement can be made for either way depending on your application street or strip. Most strip diehards disconnect the vac and dial all the advance into the initial and mechanical combined so that at wide open throttle all the advance is present. I recently went to a car sho
