Alright, I've been junky vehicle looking and found a place that had several 70 & 80s type stuff, which would have what I was looking for a 73-80 12-bolt differential for a 2WD 1/2 ton truck with the 5x5 bolt pattern.

I took one home that supposedly had a posi in it (nope, figures) but had what I would call the "BIG BRAKES" on it, larger than the other 12-bolt truck rear end near it.

It followed me home, I pulled it's pan to find a good gear ratio (3.73) which matches what I have in the truck right now with the 10-bolt.

Anyways, I'm still having second thoughts about this thing on whether it's really that much better than the 10-bolt is/was.

So, one big question, since these things are supposed to be a "bolt-in" replacement for the 10, how bolt-in are we talking here? I mean, I want the driveshaft length to align just like it did with the 10. I don't want to have to shorten or lengthen another one, this last one (for racing) cost me a pretty penny that I'd like to keep and use.

I struck out 100% on the 14-Bolt SF with 5x5 (out of a 454ss pickup) those things are impossible to put your hands on, and I need a little stonger solution, like now.

Thanks!