BB performance question:

[franko72]

My 402 BB has me stumped. It seems to really run strong when it I punch it down at 30 mph. It doesnt turn the tires over from a stand stiill run. I thought that a BB should fry the tires from a starting position.I have the timing adjusted and the rpms are correct. I checked the vacuum at idle with motor warm and get about 12 to 15 inches of vac.I bought a rebuilt carb.hoping that it would help. no difference.The motor runs quiet , doesnt miss or stutter.Idles perfect,starts great. just doesnt seem to have the power that I think it should. any suggestions?motor has 125,000 but doesnt use any oil. Its a C20 with 3:54 gears 400 turbo.I have adjusted the valves also. need some answers.