I'm going to pull my Stage 1 manifold soon and plug heat riser crossover in the heads on my coupe. In the meantime it has been recommended I use a 1" Phenol spread bore spacer to help control heat under carb and improve fuel/air density. This car is a hot rod/driver not a race car. My interest is good driveablility and mileage (not that I won't get on it from time to time). Will the spacer cause the carb to run more lean or more rich? Will I have to modify the setup. It's a 73 350 w/TA Stage 1 and Rochester Quadrajet.
Yes, it is a good idea to use an insulator between the carb and the manifold... I used to use plywood sealed with gas proof sealant to keep it dry. If you do plug the heads I suggest drilling holes in the plugs to allow some heat... If the intake is too cool the car will take a long time to warm up after a cold start. :beers2:
There is no way i would plug them on a street carI pluged mine and had to pull the manifold back off and take the plugs out. Car was never right with them pluged
