i ran a bbc that was kinda small and it ran awesome.. it reved like a small block... still have it here is the combo
454 30 over, 6.385 h-beam rods , steel 4inch stroke crank, srp 26cc dome, 320 cc procomp heads mild port work, compression was 10.86 to 1 with a 39 thou gasket and piston was 5 thou out the deck, cam was comp xtreme energy grind 660 int 666 exh, i beleive it was 11-773-8 set 4 degree's advanced, 38 degree's timing, team g intake with csr 1 3/4 spacer, 1090 king demon carb, powerglide with 1.76 first and 5600 stall brd 9.5 converter in a 1980 z28 with 4.56 gears and 32-14.5 slicks and car weight is 3000 lbs with me in it..
best was 6.35 at 108 mph in the 1/8 and 9.91 in the 1/4 at 135mph 1.29 60 foot
average was 6.40 at 107 in the 1/8 and 10.01 in the 1/4 at 133mph 1.32 60 foot
leaving at 4400 on the brake and shifting at 6400....
i would be looking into the duration and cam event timing and because on a pump gas motor you want a cam that will help you build cylinder pressure and the xtreme energy grinds do this. also make sure you have a good converter builder because you may have a converter that is lazy of the line... i use Brian phaze from bdr in buffalo ny, he has been dead on the last three converters i have bought for different motors and cars, he asks all the questions such as all the engine parts and drivetrain...
just my opinion...