There is a photo of the GS intake on page 245 of the book Chevrolet=Racing? Sure looks the same to me.
Perhaps Augie Pabst was somehow involved. He was a racer and insider at Chevy in those days-he owned the "Cherokee" '67 Camaro show car for years. And he lives in Oconomowoc, just down 94 a bit.
http://mecum.com/auctions/lot_detail...D=SC0509-79381