They are not the same, quite a bit different actually. The 650 will fit on KZ750 Twins and 900/1000's although the MPH scale will not be correct for the 900/1000. I would look for a correct 550 speedo you see them on ebay often sometimes NOS even. You will have to check the Kaw site to be certain but I believe the 440 LTD and possibly the CSR 305 used the same speedo that you have. Hope this helps.
Andy
Akron, Ohio
80 Z-1 Classic-Sold
84 GPZ1100
79 KZ 1000 LTD
78 KZ 1000 A2
77 KZ 1000 LTD-Sold
76 KZ 900 The definition of a barn find
76 KZ 900-Sold gone to Denmark
KZ 750 times 3, KZ 650 times 8 Sold 1 down to 7
KZ 550 times 2 80 440LTD-Sold
81 CSR 305-Sold 81 Yamaha XS650 Special
