I need a little help I'm working on a freshly rebuilt 71-72 464 8.75-1 CR. performer intake & 750 carb, T/A headers, stock heads, T/A cam 288-294 advanced 4 deg. (using T/A timing gear set) in a 70 skylark. It don't even want to start with out at least 20 deg. base timing but seems to run strong with 25 deg. base so 1.st off I know the CR is low for the size cam and I know that lower CR. engines like more timing BUT 25 deg.!!! and also going not wanting to start to running strong with just a 5 deg. change. Other info is it has a new balancer, the distributor is a factory point type with a Mallory HEI. conversion with re curve kit (limit bushing and the lightest springs installed also I made a stop for the vacuum advance unit limited to 10 deg. and I run it to full manifold vacuum. when I check the timing the engine is warmed up with the vacuum line removed and plugged idle at 600-700 in park. I know that every engines timing is different but 25 deg. normal for this kind off set up. Also by chance did advancing the cam 4 deg. do anything to the base timing. Or am I just overthinking this to much. Thanks in Advance to Everyone.