I have a question?
Every single 2001+ year model LS1 or LS6 engine had the same intake manifold. It doesn't matter if it's a base Z28/SS Formula/Trans Am/WS6/Firehawk base Corvette/Zo6 they all got the LS6 manifold from year model 2001 and beyond.
Nothing before 2001 had the LS6 manifold.

