Having "DANA" stamped on the ring gear pretty much tell me what the diff is, it is a Spicer (Spicer and Dana are the same company). You'll want to look around on the housing, possibly on the center section near the cover on one side or the other, or on the top of the snout above the pinion, for a cast number. Most likely either a "44" or "60". That will be the model of the differential. Both are good axles, the 44 being equivalent to the GM 10 bolt, the 60 a little stronger than a GM 12 bolt.
As far as the gearing goes, if you don't go too big on tire diameter, you'll probably be ok. If the transmission came from a Chevrolet, I believe that the bolt pattern is the same.
