[skidlids]

As I have never fitted a 6-speed gearbox I would only be guessing, But Wayne went for one from a bike with a dry clutch (ST2 I think he said) and found it to be different, I might be wrong but I think the shaft is longer, so probably a few issues with aligning the primary drive and also not having your pressure plate grind through the clutch casing.

There are probably 4 or 5 people looking for a 6 speed gearbox at the moment so finding a cheap one may prove hard.

If I was looking for one I would be condisering a gearbox from the following models

Late 620s
695 Monster
696 Monster
800SS, Monster, S2R
1100 Multi with the Wet Clutch

But as I said I haven't tried it myself so can't say for sure