There are plenty of people on here who know more about these bikes than I do but I'll give it a shot. We recently bought a '69 and a '72 CL350 and they are mostly the same bike through the years. As far as I can tell, the engines are the same through out the years and they are the same as the CB models. The forks are different. Of course, the exhausts are definitely different between the CL and CB. Within the CLs though, my '69 exhaust looks different than the '72 but it will bolt up the same as far as I can tell. The side covers are slightly different with vents added in the later models but they still fit the same. By far though, the biggest difference is the seat. The '69 seat flips up front to back, the '72 seat flips to the side. I think it changed at the '70 to the 71 model but one of the guys can verify that. The other thing I have found is on my '69, the front brake cable is different. It has a wire coming off of it to trigger the taillight. The '72 has a separate wire coming out of the switch pod. I can't get the '69 brake cable anymore. If I can't find one on ebay at some point, I will have to change my right pod to a later model and run the wire separate. Keep this in mind if you need switch pods.
Oh, the rear light changed a bit but will fit to the bracket either way as far as I know. Also, the idiot lights changed the last year to a setup between the clocks. Ours have them in the clocks.
There may be other things, but that's all I can think of right now. Very interchangeable though. Just not the seats so much.
Hope that helps.
