Ls2 intake on an ls1
If you're LS1 is near stock, the LS6 intake should work fine for you. If you have a larger cam, free flowing exhaust, aftermarket heads, etc - A ported LS2 or FAST 90mm intake should help you out.
LS2 guys have been reporting 10 to 20rwhp increases having the intake properly ported. That's pretty close to those that put on FAST 90 intakes.

