gs550 head stock bearing differences

[Guest]

Hi everyone, I'm in the process of putting back together a dis-assembled 1980 GS550. Today, I went to fit a new front end to the bike today and noticed that the lower head stock bearing on the replacement front end is too big for the frame. I'm guessing that the front end I'm trying to fit is off a GS550 from a different year. Does anyone know if I can just take the bottom bearing off and replace it with a smaller one? or do I need a different front end?

[Grimly]

Do you mean the outer ring is too big, but the stem size is the same on both of them?
If so, you could find a bearing with the right stem size and the smaller outer ring.
Dotheton.com has a list of swaps and head bearing sizes and you'll find on that the right bearing for you.