8.8 swap

Do it right with all new bearings and races, mark your carrier bearing caps as to which side is which and their orientation, note which side the shims came from, keep track of the pinion shims. clean the inside of the housing really well. Grease your new bearings well. Rebuild the limited slip clutch pack while you're at it with new clutches. When you get the axle tube shortened and rewelded, go ahead and have the axle tubes welded to the center section housing. Invest in a 1/4" drive in-lb beam style torque wrench so you can measure your pinion preload once it's reassembled. Get a machinists dial caliper and magnetic base if you don't already have one, so you can check your backlash while assembling. If you think you're gonna want different gears, do it now. Lastly, it never hurts to get a new diff cover, especially one with a magnetic drain plug to catch metal particles and make changing fluid easier. Use a limited slip additive with your regular fluid when you fill it.

The rear end is the cheap part, be prepared to spend another $400+ on new bearings, clutches, races, seals, fluid, etc. Having just rebuilt my own 8.8 to prep it for install, I'd say the biggest piece of advice is take your time, do it once and do it right. If something doesn't seem right, do not move forward until you are confident you've resolved the issue. It's much easier to do everything correct now, than to fix a mistake later.