I just ordered a new piston ring for inside my fork tube. I didn't notice until today that there was two different rings per serial number of the bike, and I ordered the wrong one based on my serial number. Does anyone know why the piston ring in the fork would be different for forks on the 1977 Honda CB750 up to serial number 2707507? I can't imagine they are different sizes since the lower rod that holds the piston ring is the same. it does show two different fork tubes, are the inner diameters different on the fork tubes?
part number 51437-400-771 vs part number 51437-329-010
