I have a CB350 and a CL450. I wish it were the other way, as my plans for the 450 are more along the lines of a cafe racer look, so I'd prefer to have the CB style exhaust on it. Besides the obvious problem with the location of the mounting brackets, are the exhaust ports on the 350 and 450 the same size, so I could swap the pipes from one bike to the other?
(I don't currently have the bikes stored near each other, or I would just measure them, or give it a try.)