Quote Originally Posted by fmg camaro View Post
What do you mean?
the rpm of bigger head 220? if you went to the bigger port runner you may find that lower rpm power may not be there as if you use a smaller port head . so with a bigger port runner you may find your self past the rpm range of you cam .maybe more to the point valve train /your roller lifters .many have used stock roller lifters past 6000rpm. but they make a short valving lifter more or less a soild roller lifter . it has min travel for pre load .this lifter helps you run a bigger valve spring to help keep lifter on the cam for more rpm this lifter help keep valve float down were with a stock lifter the valving can have over 060 in the lifter when they float or start to pump up you have a better chance valve train not all bent or busted off