[lukecp]

You could just try a 1/4" thick carb gasket if you don't already have one. Get a good Fel Pro gasket. They are made out of black gasket material, and have crush limiters so you can't overtightnen them. They cost about $10 or less at the parts store. They won't have one for your application since GM used Qjets, so you will proably have to go dig around and find one in the Holley pattern. I ended up buying one for a Chevy 366-427 engine out of a C60.