i think 400ish hp the max any body get with the 302s and 920s! thay run outta material to grind outta them heads for thay open up enuff to make any more! the 302s HR ported for there junkyard jewel cracked up shortly after there artical was printed! now id love to see a 318 with a well ported streetmaster head and a max effort build! heads make the HP! bore an stroke determine when in rpm range it makes it!!