[my427cobra]

I'm learning so much here as I shift through all the responses:

Cast iron cases: 1963 to 1975

Aluminum cases: 1976 to 1982

Auburn Posi: 1963 through 1967

Warren Posi : coded with a "W" suffix in 1968 through 1970 otherwise Auburn

So I'm looking at Tom's pictures of his adapter:

He appears to be using a Dana 44 rear cover (with filler plug and breather), bolted to the rear of the adapter.

The adapter appears to be fastened to the diff housing with countersunk fasteners in the Corvette diff bolt pattern.

So you use a Corvette diff gasket on the front side and a Dana 44 gasket on the back side

Am I right so far?

Cheers
Greg