used 3.73's

Don't waste your time on used gears if they have obvious signs of wear. They are going to make noise and possibly eat up bearings. Go with a new set and save yourself the time of rebuilding it again.

Look at it this way, how much is a complete set of bearings, races, gear oil, and pinion seal? Add that up and compare it to the cost of a new set of gears. The difference is what you are really risking. You figure if these gears take a ****, then you will not only need to buy new gears...but you might need to replace all the bearings and races, plus the pinion seal and oil.