Used coolant crossover tube.  This is from an LS6 engine which only crossovers on the front.  Can be used with most LS intake manifolds.  Some minor rust on the hose nipple.  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