LS1 vs LS2 compatibility
Make sure to get a GenIII iron block and your 408 will be absolutely compatible to the last bolt.
You do want to consider what the previous poster said. If you get heads/cam now, then you will either need a set that's optimized for the current block and sub-optimal on the new one or vice-versa. (or a compromise between the two).
Personally, I'd get the heads intended for the 408 and the cam optimized for those heads with the 346, and budget a new cam with the iron block conversion. That way you are still pretty good with the current motor and then optimized on the new one.


