Let me start out by saying these are technically too big for the GS500 - they will fit the mounts, and you'll need some type of pod filters (K&N lunchbox will fit just fine). But the model is BS36SS, so they have a larger throat diameter than stock. Same type of jets as stock, but you'll definitely need to work to get the jetting down.
(http://i598.photobucket.com/albums/tt70/rmyers104/GS450%20S/20130605_082033_zpsde30ee36.jpg) (http://s598.photobucket.com/user/rmyers104/media/GS450%20S/20130605_082033_zpsde30ee36.jpg.html)
I'm asking $50 shipped to the lower 48.
Adidas and I were talking some time back about larger bore carbs.
So...... Adidas, what do you think about these? Smaller jets should not be an issue.
Just want to add: I'll throw in used GR650 throttle and choke cables as well. They will be too long overall (remember, the GR is a mid 80's cruiser with higher bars) but they would have the correct amount of slack at the ends for the GR carbs.
When I put GS500 carbs on my GS450, I had to get a GS500 throttle cable for the same reason: needed proper travel of the cable.
Bumpity bump.