The bike is now running and almost done. A few things I didn't know to begin with.
Follow Brian's instructions and the only mods you need to do are removed of a couple little brackets around the motor.
The XR stock throttle and clutch cables work great. Don't use the NSR stuff just carry the XR stuff over. All good.
I was lucky and able to find a pipe that had already been used on a NSR XR conversion. So the fit was already done. I just had to hose clamp and safety wire some stuff.
Make ke sure to heat wrap all of the exhaust. If possible the can too. The heat is going to melt the underside of the NSR bodywork. Or on the can put a heat shield on the underside of the NSR tail. I had to bend the center crossbrace of the subframe to ensure the can didn't hit the tire when the read was loaded up.
The XR kickstart won't clear the footage and brake. Need to find another with a shorter arm. Or one that the arm kicks out wider.
All told old this was a super easy conversion.