1977 CB750 exhaust

[timsturmband]

I have a '77 cb750f super sport. I'm new to motorcycles and one of my first projects is trying to replace the muffler on this thing. the old one is a kerker. Is that aftermarket for this bike? Does that mean that the headers and the rest of the exhaust system are probably aftermarket as well? Are mufflers fairly universal or will I need something specific to this bike? Does anyone have advice on where to get one? etc...