This is what i got. This is what i wanna put in it. Any advice would be appreciated

Not beating on it? A junk yard Ford 8.8.
MoPar wise, an 8-3/4 or DANA 60.
IIRC, its Moser sells both new, all new, nothing used. A little pricey, but we’ll well worth it.

An aftermarket DANA 60, Ford 9, they’ll probably be the very last rear you’ll ever put in the car.
I’m not sure how strong the Ford 8.8 is. The Chrysler 8-3/4 & 8.8 Ford will handle the 440 just fine so long as you don’t start introducing 600 ft lbs of torque and hammer the crap out of them.