Okay so i came across this 79 CB750 frame with a Kawasaki swing arm with the mono-shock, a 81 CB900 engine and kaw forks and wheels. a real old school fighter. so i bought it and took it out today and while cruisin at about 105 (not really sure because no speedo) my rear pipe breaks the weld and falls off. (hack job) my question is should i look for the slip on for the 750 or the 900? what do you think?