I never understood why the LS2 is referred to as the Gen IV and the LS3 as the Gen V. They're both the same type and design as the LS1 save for a few non-interchangeable parts. I don't know....to me the whole LSX family is the 3rd generation of GM engines. An engine would have to be completely new from the ground up and have little in common with the Gen III for it to be considered a Gen IV.
But then that's just me thinking out loud again.
