I took the vavuum advance off the carb and plugged off the carb port,set timing at 10 degrees and it seamed to work perfect.What does this mean.Is my vacuum advance on the distributer shot or what.
I dont think your vac adv is shot. It is simply pulling the dist in to a condition with too much advance. There are ways to adjust your total vacuum adv on some vacuum canisters by sticking a small allen wrench down the vacuum port of the canister. On this website people have elaborated which years and distributors have that feature available.
I simply run our mostly stock 74 440 with the advance diaphragm not connected at all. It gets plenty of advance with the centrifugal advance only. I have tried the unit hooked both to manifold and to carb advance. Both variations made the car run poorly at mid range cruise. So, I leave it disconnected, tossed the hose and caped the open port on the carb.
