swapping out ring and pinion 7 1/4

According to the manual, you need a differential spreader to remove and reinstall the carrier in order to get the correct preload on the bearing.

There is also a special tool for measuring and setting the pinion depth, but I did my by trial and error with gear pattern marking grease.

Bearings and seals are available. You might have trouble finding shims.
I have a bunch of shims when you get to that point. All other parts are out there. I blew mine and took a year to finally find a new sure grip cheap.