I also found this note on GM Parts Direct for a specialty intake manifold which references that head. Apparently the head is used in a hybrid engine with 'Pontiac' head and Chevy block. Much better 'hybrid' than a Prius
10093389 Intake Manifold
This aluminum intake manifold is designed for use on a Chevrolet small-block V8 with a Pontiac cylinder head (P/N 10093328: A roll-over V8 type head). It has standard Holley carburetor flanges.
10-12-2012 12:36 PM
Based on what you're saying, I'd guess it to be the Brodix "Track 1", originally designed by Pontiac for "cup" cars. It's a Chevy head. it says "Pontiac" in big letters and has arrowheads, right? It does NOT "fit" the Pontiac.