My small block was running awesome!! 350 30over 202 fuelie heads 10:1 solid sig cam 510/ 287. I had set the timing by ear. My buddy checked the advanced timing for me with his ajustable timing light. He said total advanced timing was close to 5000. He took it down to 4000 and said the way I had it would burn the pistons. And now it just doesn't run right. Doesn't sound as good at idle and misses. Book says it should be about 3600 total. Why does it want to run better at much higher advance ?
5000-4000-3600-is this RPM or degrees. To check this 1st unhook wac. advance. Use timing light to check timing at idle (12-14* good starting point). Next rev engine slowly to see when mark stops moving. This figure will be your total timing. (example 36* @ 4000 rpm). Sounds like he set it with vac can hooked up-some can have as much as 20* in them-causing your idle timing to be to low. Set it back to your "ear timing" and you should be fine. Your total timing will never be more then idle timing + centrifugal when you are at wide open throttle.