["Guy]

Gp76, Sounds like the mechanical advance in your distributor is advancing just below idle(800/1000rpm). The mechanical advance should never just start coming in at idle it has to be just above! I donot think you have a vacuum leak...To tune this car right you have to start with the distrubtor. Have a "good" shop that curves distributors put the right curve for your build of "your" car. They'll ask for all engine specs(cam/carb/compression/headers/etc.),weight of the car, gear ratio,auto or stick, and what you want to do with it(drag race/cruise). Anyway you have to have this right first before anything else can be tuned! Who knows some have made another 40hp just getting this right! After you get that done give me a call...I'll help you thru the rest.