4.8 vs. 6.0
the 4.8 and 5.3 have the same block though

some 5.3/4.8 (which, btw is how they are labled on the back of the block) have been bored out to accept 5.7L pistons, in effect creating an iron block LS1. But that is pusing the limits, you might as well get a 6.0L and roll with it if you are looking for an iron block



