Ok, update on this for any other interested parties. I’d read on the interwebs that some people switch to KX250 clamps for the quote on quote “more favorable offset”. The ‘96-98 KX250 clamps are the same 22mm offset as the factory KX500, and are the same through 2002 if I’m not mistaken. The 2003+ KX250s are 25mm - perhaps someone would think the greater offset would be better for straight line stability, though 3mm seems a big shift for an already decently balanced bike. This is why we don’t trust things written on the internet
Anyways. The only difference for the KX250 top clamp that I bought was the size of the stem hole. We are going to machine a bushing to take the slop out, and run the 250 top clamp on the 500 lower with 500 bearings.
All this because some schmuck decided to cram a Honda top clamp on the bike so he could mount a modern front plate (It wasn’t an aftermarket clamp after all). The offset was certainly greater than 22mm, and the space between the stem and clamp was egregious. All this for aesthetics.
Come on folks. We’re better than that.