New Dorman coolant crossover pipe and block off kit.  This crossover tube attaches to the front of the heads when you use an LS1/LS6 intake, or any of the higher performance aftermarket intakes such as FAST/Wilson intakes.   Includes seals. Fits the following:

98-02 LS1 Camaro Z28
98-02 LS1 Trans Am
97-04 LS1/LS6 Corvette
04-06 LS1/LS2 GTO
04-07 LS6/LS2 CTS-V