Sorry to bother you all again with yet another question Does anyone know if the upper forks of the 600ss carby are a straight swap for the 900ss ?
As you have a 900, the shocks are most likely to be Showa; whereas the majority of all the 750s had Marzocchis and IIRC all the 600s had Marzocchis; so in a nut shell, I would say it is highly unlikely.
If you mean fork stanchions, then they are different. When I was looking up new tubes for my 750ss I found out that they are the same for the 600 & 350 -but not 900.