Not heads at all... you have other issues somewhere that gear still is killing it, 10" is not right for it unless its street driving also ? The 8" made for a low 10 second car should be wayy tight for a 1120 car, we have cars going 1.70's running high 12's most your issue is in the first 60ft .. hence the converter/gear issues I keep speaking of. You have far from enough motor for the 10" in a all drag race purpose