rear end question

I must doing something right I pick up this parts car for 100 bucks and it turns out to be a 8 3/4 sure grip rear end, a V8 K frame with a sway bar, plus lots of extra parts. Then I go to the local pick and pull yard and find an roller 318 out of a 86 Dodge truck, and the motor is almost spotless.
Knock on wood; turn around threee times anything to keep this going.