Replied on February 13, 2012

that must be why gm discontinued it, what happened is I replaced the engine . the plate was there by factory oem. the system is non-egr equipped and they changed it in mid year production to having an egr system. I dont know why, I think ill do as you said and just make one. I have the diagram from general motors and it shows the part and part number, but was discont. The exhaust shoots out of the intake side of the head because the port proceeds through to the exhaust side.

Response from ronebiz