I am not sure if this is where is should post this...

I am going to be making a set of Billet Valve covers for my 1957 Bel Air convertible. I know I can't find aftermarket covers that will fit my needs.
I am going to be milling the square pattern on the valve covers that will match my Magnuson Supercharger.

Does anybody have a drawing of the mounting surface with the groove for the gasket? I could measure everything but it sure would be nice if sombody
had the information.

I am fortunate enough to own a machine shop.

thank you in advance for any help.

David