Yes, the GB500 "Tourist Trophy" bars will fit. They're 35mm and made with a post on the bottom that engages the upper triple clamp. However, they are not readily available so if you've found a set, better grab them up. Also, they come with internal bar weights and end weights that slide into the open bar. Get it all.
There are other, easier to find options available for adjustable bars, though. Most can mount above the upper triple if you set it up that way. RR