Silvio, I don´t know if you´ve gotten your question answered yet, but I´ll throw some ideas at you. A number of carbs can and should fit your bike. I think the 81-83 models are similar. You can go to www.buykawasaki.com and search for the part number for your carbs and see if it cross-references with those or other years. I believe that the GPzs used mikunis so you should be able to find comparable carbs from other makes. Just measure the outlet side of the carbs (side facing the engine) to determine what size in mm your carbs are. You´ll also want to make sure any carbs from another make have the cables hook up in the same place. For further info, try this website: http://www.gpz550.com/scripts/forum_gpz/default.asp