8.25 questions

Just picked up an 8 & 1/4" rear end for my 72 Scamp. The 8.25 is casting 2852905. It has approximately 2.75 (so I assume 2.76) gears and open carrier. I was told it came out of a 74 Dart Sport.

I've done some reading and it seems I can get the sure grip unit and gears out of a pre-96 Dakota and it'll fit right in? Is it also the case the axles are 27 spline?

I plan to redo the brakes, put in a new carrier and gears, and put in new bearings. Is there anything else I need to do? I've never dealt with this end of the drivetrain before and want to make sure I cover my bases.

Also, would you guys steer clear of a used sure grip/posi unit and gears or what? I've got about 280 HP and don't plan on ever exceeding 400 at the crank.

I assume I will have to shorten my driveshaft, too? Thanks for any insight.
Picture is with the 7.25 2.76 gear peg leg on a piece of steel.
Burnout.jpg