I got an adapter from Buffalo. Fits up nicely. I have it behind a 302 with a GM cast iron bellhousing with factory angled mounts on the bellhousing(factory.) The transmission is a NP 540-but the transmission doesn't matter. It has not run much but will get more when the tin work is done. Great way to get a modern starter and transmission. Make sure to dial indicate to make sure everything lines up. .005 +/- is max runout.
Ed Pruss
Longmont, CO