Used rear block cover for 1997-2012 LS based engines. Casting #12572014.  This cover has the rear main seal removed and is ready for new seals (not included).  This cover has the wide oil transfer groove and the thin bolt bosses, which requires the short cover bolts (not included).  Fits the following:

97-12 LS1/LS2/LS3/LS6/LS7 Corvette (all models)
98-02 LS1 Camaro Z28
98-02 LS1 Trans Am
04-06 LS1/LS2 GTO
04-07 LS6/LS2 CTS-V