TOPIC:

I am in search of a set of tubes for an 81 GPz-550. doesnt have to be off a GPz, anything that fits would be fine. i think any KZ550 from 80-81 would be the same . tubes are 36mm. would also be interested in full assembly if the price is right. tubes need to be clean with no pitting. shipping would be to Toronto, ON M5E1E6. let me know if you have anything! bought my first bike and as a complete noob didnt realize one of the forks is badly pitted.

I think some models have longer tubes and air adjustability.

But the lower legs of a single-disk model in the U.S. is not compatible with the Gpz brake discs. Even though the legs look the same, the mounting point for the caliper is farther away from the axle. Thus the pad won't sit fully on the disk. You will need Gpz for legs or larger disks.

If the pitting is not in the area where the fork seal ridesa, you should be OK.
Most suspension shops can send out your fork tubes to be recheomed.
This place is well known for new fork tubes:
franksforks.com

Good luck on your repair.