One of your other posts caught my attention. Correct me if Im wrong but LS1's come with LS1 heads. Z06 heads are LS6 heads...that is why one can put LS6 heads with '01 and '02 models because of the intake manifold. Then that leads to the price not being worth it as one can put long tubes, a cam, and dyno tune and make 400 to the wheel a lot cheaper.

 

LS1s come with LS1 heads, but 2001-2004 LS1s come with the LS6 intake manifold.

You can use either on either, but the LS6 stuff (both heads and intake) is better.