Hey guys. Quick question. I have a '78 CB550 and I'm going to extend the swingarm on it. I have a spare frame/swingarm from I believe a '76 (10/75 build date). The swingarms look pretty close, but I just wanted to see if anyone knew for sure they are interchangeable? I still need to check the measurements, but the spare is at my storage unit and I need to make a trip to pick it up, that's why I'm asking here. My plan is to extend the spare than swap them out once it's extended, but don't want extend it and find out it doesn't fit.