Just spitballing here-
The SBC uses flat plate mounts on the side of the engine block. Guess what? So does the Magnum. (in addition to the 340/360 ear mounts).
You could probably just drill a flat 1/4" plate to accommodate the Chevy and Magnum mount patterns. You'll just need to come up with a trans mount plan.
*Edit- You beat me to it!*
