I second that. It didn't work too good on my friend's race SV until we made a new shock linkage.Just so you know, it will fit, and give you a tidge taller ride height.
But the shock linkage ratio is completely different between an SV and a GSXR.
The SV swinger has a lot more leverage over the shock.
SV650 (99-02) 650
SV650 (03-06) 500
GSXR600 (97-00) 425
GSXR600 (01-05) 400
GSXR600 (06) 500
GSXR750 (96-99) 425
GSXR750 (00-05) 425
GSXR750 (06) 500
GSXR1000 (01-04) 450
GSXR1000 (05-06)) 475
The GSXR shock will be fine for street, but if you take it to the track (especially if you're fast)
you'll find it too soft without a respring/revalve.
Then you might as well buy one ready to go.