if you do alot of research there are alot of people that are blowing up there LSX motors with the sts kit. I personally know of a 03 GTO and a 01 SS that popped there motors, both went to 6.0L cast blocks and a front mount(i guess thats what you call it in comparason).

before the pop they were both in the 450-550 range to the wheels with supporting mods