318 and 10's

as I pointed out previously, it can be done, even with a 273 and no power adders. There is no rocket science here, the engine has to pump the air...a smaller engine has to turn more rpm to move the same amount of air.... The other thing to consider, is that valve shrouding is worse the smaller the bore gets. A head will flow more air bolted on a 4.040 bore than it will in a 3.900 bore. How much do you lose there? I do not know. Then guys all start yapping about the chevy LS motor, but they don't relize that is a 15 degree head as opposed to a 18 degree, or even worse the regular chevy 23 degree. So all that plays into effect.