The diffrent timing covers is what always confuses me with Fords.. I wouldn't worry about the bearings,I'v had to change pully's from serp to V belt on alternators before, my guess is the bearings are the same.

Gets confusing when you have to order parts for a 1989 when your working on a 1992, and all because Ford continued to use the V belt setup on some engines for a couple years ( Ranger 2.9L ). Then the rebuilt alts that Advance sells have the wrong pully's cause the books on what is correct is wrong....