8 3/4" sure-grip swap and rebuild questions

It has too much pinion gear depth. You need to back it out a little.

Also, FWIW, I don't use a gasket on 3rd member style rear axles. RTV only. It's always worked well for me.

I wouldn't be surprised but I just straight up don't have the energy to pull this thing and take it apart for a third time. I thought about putting a .038" shim pack behind the pinion (has .039" now, started with .035" and that was too far "out") but I was sooo over it I just ran out of patience. Already threw about $80 in the trash doing it a second time. I know it's the right thing to do but I just can't bring myself to do it. If it was still reasonably warm outside and didn't get dark by 5:00PM I might be more motivated. Also just a lot of stress from other life stuff like applying for jobs and keeping up with going to the gym, cleaning my house, feeding myself, taking care of my cat, putting up with a job I don't like etc etc. I need my Duster running because it's the only way I can really release after a rough day. And boy these gears made it quite a rush, with all the BS I'm still glad I did it. Being able to get rubber all the way through 1st gear is just fantastic.

I've successfully used RTV as well but I HATE having to spend 30+ minutes scraping off every last little bit of rubbery goo so it seals on the next install. The paper gasket seems to be holding up well I don't see any seepage from the case/housing. I just want to be able to swap center sections quickly. Which reminds me I still need to bolt my 2.94 ring gear on the open diff I took out of the 489 case and put it back in my old 741 case... who knows when that'll happen.