Update on the project and a slight tutorial.
How to fit a ZRX1100 swingarm to your Z1000 Mk.II
First, remove roughly 2-3mm of material from the right hand side of the swingarm (enough so the swingarm slides into the frame with ease), since you want to keep as much material left as possible on the chain side of the swingarm pivot so you don't have to get a massive offset sprocket.
Once that is done, fit all the bearings in the swingarm. Big needle bearing on the left side, smaller needle bearing + support roller bearing on the right side. Make sure you fit the support roller bearing as deep as it can go.
After that, it's a matter of modifying the swingarm pivot tubes. For this we use the ZRX tube and the stock Mk.II tube. The nice thing with this is that you can shave off a bit of material from the Mk.II tube and it will fit inside the ZRX tube, like this.
The ZRX tube gets shortened 2mm and the Mk.II tube gets shortened 6.5mm. If you do it like that, the Mk.I tube will slide right into (after you've machined the end of the tube a bit in the lathe) the support roller bearing inside the swingarm, like this.
The other side of the tube should now rest flush with the dust seal on the left hand side of the swingarm!
After that it's just a matter of fabricating a small spacer which is 25mm outside diameter, 16mm inside (the swingarm axle diameter) and roughly 10mm wide (give or take a few tenths depending on how snug you want the fit to be).
If you need to make any adjustments, all you really have to do is adjust the width of the spacer on the right hand side (the one described above). Fits like a glove in the frame and doesn't move an inch when you tighten up the pivot bolt.
All in all I think it was two hours of work.
I'll grab some more precise measurements tomorrow.
Next up is welding the shockmounts. I'll probably start with that sometime tomorrow.
There's no replacement for displacement.