swingarms.com

Obviously I haven't tried every GSXR arm in every KZ, but I have run my bike with both 600 and 750 arms, and checked that a 1000 arm would fit, and there are various other Suzuki arms including a Busa arm mounted in 750 turbos on my site.

I also know that ZX6, ZX9 and ZX11 arms are all approx 1" too wide. They can still be fitted with some surgery, but the Suzuki arms generally go in easier.

What else will you need? You will need an offset front sprocket (assuming you are using a wider donor wheel), usually you will have to machine the sprocket carrier on the donor wheel, conversion to 530 chain makes clearance a lot easier, the swingarm spindle will need a sleeve (on the turbo the standard sleeve fits inside the Suzuki arm conveniently), and you will need to space out or replace the footrest hangers to clear the wider arm. The more donor bits you have from the bike the swingarm came from the better. Don't forget the chainguard, spindles etc, a complete rear end is ideal. If you are mix-n-matching bear in mind there is quite a lot of work involved in aligning everything, caliper hangers, spacers etc.

Oh yeah the year doesn't matter much. The bracing arrangement varies, and the caliper mounts, but not much else. Bear in mind if you are going for twin shocks that the arms are wider on the left than they are on the right, to allow for the chain run...