Please help me identify this Tri-power manifold
 

I am selling this manifold for a friend. He had it on his 67 Firebird. I know nothing about these manifolds. Is this a common tri-power set-up? Was it exclusive to the GTO? Any and all info appreciated. I will try and post pictures below.


http://s32.photobucket.com/albums/d3...t=IMG_2027.jpg
http://s32.photobucket.com/albums/d3...t=IMG_2029.jpg