Nomad - if you can post a pic of the underside of the GL stem, it may be possible to have it "pushed" back out to shorten it. Not always possible on factory Honda stems due to them not having enough throat profile on the topside of the lower stem.
If it can't be shortened that way, then another option is to have it cut in half, then shortened, then plugged and welded back together to the proper overall length. Understanding this:
- only the top and bottom portions of the stem are under direct stress.
- rigidity of the stem matters, and the new "connection" must be as strong or stronger, and the interior plug should be pinned.
- grind the welds on the modification down to pass thru the bearings, and install.
OR, have a new stem pressed into the GL lower from a 550. More than likely the seat area is the same and the stem bottom is the identical measurement in diameter. I'd suggest spot welding the new stem into place for assurance.
Make sense?