I put the standard internals in an OD case and that is in my car right now. Since I was using the OD bellhousing as well the bearing retainer fit just fine.
However, I had to still use the cast iron tail shaft. The OD trans has a the smaller output shaft. You can buy an aluminum tail shaft...
That's the NV3500, I have one in my Dakota. I've managed to run high 12's with it, but I leave like there's a cop behind me and shift like an old lady. Sticky tires and dumping the clutch at 3 grand would likely explode it.