There's a member here on the hamb that was making an adapter plate from the Cadillac to a small black Chevy intake. Because they're easier to get your hands-on but I can't remember his handle.
We've got a member here that makes exactly what you need: https://www.lakeheaders.com/products/copy-of-cadillac-4x2-intake-manifold
Classifieds https://www.jalopyjournal.com/forum/threads/early-cadillac-cragar-blower-intake-manifold.1336639/
The Jalopy Journal
