Last winter I pulled out a .30 over 9 to 1 340 with stock X heads, 292/509 cam and an RPM Air Gap intake with a holly 750 carb and TTI headers. I built a .40 over 418 ci stoker motor with h beam rods and diamond pistons (10.9 to 1 compresion). I also had a set of edelbrock heads ported and I pretty much used the rest of the parts I already had. The motor makes about 525 horse power. It is in a 70 Duster with a 4spd. and a 3.91 gear. The only thing I can tell you is the first time I got into it, after it had a few miles on it of course, I almost had to go home and change. It was worth every penny.