Mixing and matching significantly different components is always fraught with ... interesting challenges. Many things can be dealt with by using different sized bearings and spacers. It comes down to try it and see. Full front-end swaps are always easier, especially when combining multiple changes in design philosophy - USD forks, radial brakes, internal vs external flux capacitor, etc.
One thing to watch for is the overall fork length - IIRC, the R1s were notably shorter than those on the FZR, leading to significant changes in the bike's geometry. I could be thinking of something else ...
You have the parts in for powder before you checked to see if they'd even fit?!
