Have you tried freezing the shaft with dry ice or nitrogen and heating the lower triple clamp. I believe that that is how Kawasaki does it; Interference fit. I would use the 05-06 wheels on mine also. Right now it has 89 GSXR 750 wheels & brakes on it with reworked stock 85 forks. I have some cousins in Edmonton, Alberta. Might have to fly up there and visit.

 

Do you have the dimensions for the top triple? I have one that I can measure but I don't know how accurate it will be. It is straight. The stock lower should be plenty strong enough unless you want your own cool looking one. I have seen the Attack Ones; they look awesome.

 

Haven't tried shinking the shaft out yet. No access to nitrogen... best i could try would be put it in the freezer then torch the clamp up to temp as fast as possible before the shaft heats up. I think i will look around town and see if anyone does this kind of thing professionally and what they charge.
As far as the top triple dimensions go, i was going to try to pull them off the lower that i have (i do not have a top right now). I was going to put the forks in the lower triple, use a micrometer to measure from the outside of the fork leg to the outside of the steering shaft (furthest possible distance) then subtract the radius of each to get the distance on centre. Have done stuff like that before, usually good to a couple thou. Throw it all into mastercam and yeah... should probably be spending my time doing it not talking about it.

 

I can lend you a top triple to measure. Let me know.