Being that you own an XS650, the answer should be apparent: it will actually work. Unless, you're one of the lucky ones whose clutch works after the motor gets hot. To be fair, though, after futzing with my XS650's clutch for years, I finally figured out how to fudge the adjustment so that I can still find neutral after the engine warms up.
I'm curious -- where have you found a kit for the XS? Most conversions I've seen have been cobbled together from eBay parts.
Actually I one of the lucky ones. HaHa. That is until the bike decides to stop shifting. That can be a bit troublesome when it sticks in fourth at a stop light but thats not the issue here. I found it at this site. http://www.geocities.com/fischervintagecycle/index.html Its in the XS section. Hes got some pretty cool stuff there.