I have used 0.020" (0.5 mm) shims in my Kehins on a Trident 900
These are available from <www.allensperformance.co.uk>
Tel:+441949 836733
I also got larger main jets from these guys, my current set up is 130-125-130 with K&N filter and std exhaust drilled out both ends with the biggest holesaw that will fit (about 20mm). Ihave only tried one shim so far but this looks to run OK and is very noticeable above 7500 rpm.
Putting a 3 into one with Remus oval race can on will make the bike wheelie off the throttle. This would be hard to do with the std bike.
Hope this helps
Tripple3