anybody know of any manuals that would fit a 472 or if anybody ever rigged one up? thanks.

The 60s/70s M20/21/22 Muncie will work if you use one with a BOP bolt pattern. The Chev pattern won't work. Not sure about a flywheel, though.

You can probably get an adapter plate to use the T56 six speed from the 93-97 F body (Camaro/Firebird).

There are a few vendors out there who have made flywheels for the big block Cad. Forget which ones though, check around and you can find one probably.

The biggest problem will be getting a shifter that works right. The 472/500 sits very far forward of the firewall to make for a more open floorboard so most shifters would be coming up under the dash if not under the hood. The dash design isn't really friendly to a floor shifter either. This is what has kept my Caddy with an automatic more than anything else. Maybe I just need front buckets and a remote shifter...

Of course, if your 472 is no longer in a Cadillac chassis this isn't such an issue.

Don't forget a pilot bushing/bearing for the back of the crank. Mine had to be drilled.