SB bell housing

You are aware that you'll also need Brewer's modified clutch bellcrank and misc. linkage parts, since the 10.5 bellhousing never came in the early As? The factory 9.5" linkage will not work, nor will the later A 10.5" linkage.
Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists (brewersperformance.com)
Making the OD trans fit your bellhousing depends on what you have.
Does your transmission have the 307 (3.70 bolt circle) or 308 (4.16 bolt circle) front bearing? ODs could have either.
What is the retainer hole diameter in your bellhousing? 4.354 or 4.807?
There are certain combinations that can be made to work, with factory parts or creative machining; some combinations that can't.
Your best bet at this point is to try to locate an OD bellhousing to use, like you're trying to do.