[Batman]

Youa re going ot run into all kinds of problems with either setup you are talking if it is for a 4th Gen. I don't know if you looked under the hood but a 572 most likely won't fit without cutting out the wheelwells. As for the LS7 you will have to re-work the heads to put turbos on it or you will end up with like a 14:1 CR, you are talking 110+ octane all the time. And don't forget the dry sump oiling system. I would get a low compression 402 LS2 engine (lots of places have them making over 500RWH now on high compression style) and then go forced induction on it. You will have as much or more power then either of the other engines and still have an extra $10,000 in your pocket. The only reason to pay for the LS7 over a built LS2 is if you plan on keeping it N/A, it isn't designed for boost.