make sure you don't see any signs of oil leaking out the seals on either the compressor side or the turbine side. Make sure the wheel spins freely, with not side to side shaft play. It can move in and out a little, but it shouldn't move toward the wall of the compressor inlet. Make sure you don't see any signs of the compressor wheel ever coming in contact with the wall of the compressor inlet(you would see scrape marks and the fins on the wheel would be show it too). 40k is kind of a lot of mileage on a turbo, but if it was well taken care of, you shouldn't have any problems. Make sure you're getting all the oil feed and return plumbing. If you have a 92-95 Civic, you can swap oil pans with him, so you don't have to go thru putting the drain fitting on your pan.