I have the GM 10185071 roller that is from the ZZ4 crate and they use it on the 604 crate (5.7). I got mine used from a ZZ4, the guys would swap them out for a different cam to go drag racing and sell the basically new cam for cheap. It works great with my vortec heads. We used the 604 crate in our sportsman and pro late model circle track cars and that cam worked well with the fast burn aluminum head.
