We have had more than one sled come into the shop with the underside of the tunnel ripped open by studs in the track. Kawasaki must have understood that fairly early since in 1980 they began offering a Tunnel Rub Strip Kit in January 1980 P/N 99970-3524. On element of that kit that I wasn’t otherwise aware of were the suspension lift brackets – essentially identical steel brackets for the support of the rear suspension cross-shaft with the exception that the mounting holes are dropped by about 1.5”
We only have one example of the OEM lift bracket - oddly enough that showed up on our 78 Intruder. That sled has just been a wealth of information for us. I have never found another pair so we started fabricating our own. I cannot say that they are too elegant, but they get the job done.
With the added height of the rub strips, it is easier for the track to bottom out. The little bit of lift offered by the new brackets helps to keep the track from bottoming out.
So for all our 78 and 79 sleds we add the lift. We also add the lift to the 80 and newer, non-vari-ride sleds.
Again, for us, this has been a good modification.