My buddies 440 dynoed at 496 horse, 500 lb/ft with a +.030 440 and ported iron heads, and a fairly mild Comp cam. 0-100 in not too many seconds.Just watched engine masters crank out 432hp and 473 lb-ft out of a stock 78 low compression 440 with a 268 comp cam and 240cc trickflow cnc heads. Yeah my vote is 440. So easy to get power just freshen up the bottom end and done.