Should fit up the same way as my SP swinger,which is the same unit except it has bracing.
The pivot point is a direct fit,as is the shock linkage.The width is about 1" more than the stock B4,so you need to make some changes back there.
The GSXR runs a bigger,hollow axle,so the bearings are different.I used a 1st gen SV650 rear axle and wheel with the B4 cush drive and it worked well, with only about 2-3mm needing to be shaved off the right side spacer.The B4 rear wheel would probably also work,although youll still need the SV650 rear axle.I wanted the wider SV wheel so my 160 rear tire would fit right,so I went all the way with it.You could also probably go with a GSXR 600/750 rear wheel and it would bolt right up since the bearings are the same,but I couldnt tell you if the chain alighnment would be OK.
Also,there is no mounting tab for the rear brake torque strut. Jay had one welded onto mine before delivery since it was an unknown/unknown at the time........