Those outer races look OK- - - -if they're not pitted it would probably be OK to re-use them. Most replacement bearings come as a 3-piece set, however, the ball cage plus inner and outer races. As long as they're assembled and preloaded properly, there's absolutely nothing wrong with ball bearings. Any good bearing supply place should be able to use the old bearing races for OD and ID reference, and find a tapered roller bearing that will swap. The tapered roller bearings will probably be a LOT less expensive, also.
One sticking point, however- - - -the surface the seal rides on is integral with the inner bearing race on the inboard ball bearing. It's necessary to fabricate a sleeve that's a snug fit over the spindle on the inside to give the grease seal a place to run when swapping to roller bearings.
Jerry
