If it were me, because I absolutely hate doing things like this over again, I'd replace the gears, since you're considering a new ratio anyway, and I'd throw in a new bearing kit. I'd take it to a shop that specializes or you know does a shitload of differential work and have them set it up.
That's just me though. I think throwing parts back in is rolling the dice.
No matter what if that metal was in the oil, it was churning through the gears and bearings and whatnot.
And a car like this. I'd run a spool all day. Yes on the street too.