I have a 1969 Olds 98 2 door convertible. (heavy car) with a 455 REBUILT .030 over with 10.5 - 1 compressions pistons with C heads (big valve I think?) with Chinese hei distributor, Edelbrock Perfomer manifold, Holley 770 street dominator car, and with 31 cam ( from 350). Not sure of rear end but being a convertible it is probably not the highest thing out there. I have timed engine to 12 before at 650rpm. Getting hesitation when I punch it and not a lot of power. I am trying for huge burnouts, rapid acceleration, etc. What do I need to do or where did I go wrong?
Thanks for any help!
Paul

 

I would look into jetting first. Sounds like it could be going lean or the accelerator pump isn't enough. Also check your total timing at say 3500 rpm. Should be around 35 degrees.