So the ring gear does have some pitting, nothing raised after cleaning up as shown in the pic. Is this ok to run?
Depends on how much your going to ignore changing that oil after you start driving it. With that much pitting, I would change it after 500 miles, then 1000, then 2000, again at 2000, and go from there. Maybe 1 more at 5,000 and put the best AMSOIL you can get in it and you should be good.
Go for it! The worse you can do is get metal filings in your bearings and seals but, you'd probably wanna replace them anyway when you do rebuild it. The usual disclaimers apply here, IMO, YMMV, etc.How it is now would it hurt to run it? I'm good with changing the fluid every so often if it would help it.