S60 is only the center from Strange. The ends depend on what they put on the end of the axle housing for your application.What's your endplay now? I had .030" on one side and .040" on the other of my Camaro. Way too much, so 1/4"+ should never see the road. It would knock the brake pads back and cause a long pedal.
A Dana 60 from a Mopar musclecar will have 2 tapered bearings. One on each side. Similar to the front of a G body. 2 tapered bearing and you set the preload with the big nut and lock it down with a cotter pin.
The set up on A Castro's S60 has roller bearing on each end and the backing plates capture each roller bearing. The end play on a roller bearing is pretty much zero. The outer bearing race should be pinched into the axle housing by retainer rings or the backing plate. Zero meaning it can not move side to side. If there is any side to side, that will be coming from the bearing, not the outer race.