They'll be loud.
The exhaust port mating interface is the same for all CB550's. No problem there. Do the ends of them have a mount anywhere?
I was really suprised that they were loud but not as bad or annoying as some that I have heard... sounding like a bunch of angry bumble bees
As to mounts, yes, at the engine end they have a round plate with two holes that mount over two studs at each outlet and at other end mounts that fir on same bolt as foot pegs.
But, My bike sets tooooooo Low to use them.
The reason I asked is I that Ihave them at ebay and the question was asked of me. and didn't know, and knew someone here would.
Thanks,
Lee