Difference between Spicer 28 and 35

Went to Advanced Auto today to pick up a set of wheel bearings for My 92 ranger with 4wd. The computer showed that there are bearings for a Spicer 28 and a Spicer 35 axle. I looked in the Haynes manual to see what type of axle I might have, but didn't show. Anybody know what to look for in the differences?

I think I had this once with my 93 ranger.If I remember right I found the sticker on the front axle and used that at my auto parts store.Of course yor sticker may no longer be there.Call around and Try a better parts store, as they may probably be better able to help you.I am not a real big fan of chain stores like advance,I really don't think most of the guys there have a clue.