Most bearing specialty places will give you a bearing specification catalog. Get out the dial caliper and do your own homework, instead of wasting the bearing guy's time. If the inside diameter of the bearing cone fits the spindle, and the OD of the bearing cup is a snug fit into the hub, the other dimensions aren't terribly important. A slightly different thickness on either part won't be a deal-breaker. If the cup doesn't fit the hub exactly, LocTite stud and bearing mount can take up minor diameter differences, up to two or three thousandths. There should be no difference in the seal application, since it only contacts the hub and the spindle, not the bearings. 1/2 ton and 3/4 ton bearings will probably be different, but I haven't had any hands-on experience with either one lately.
Jerry

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