Jason,
As long as it's a 600CFM 4160 it should be fine. It is a marine version correct and not automotive?
These carbs are generally bolt on and go. The jets are actually pretty good from the factory as long as you have the right CFM on the right size engine. Just making some minor mixture, idle, accelerator pump and choke settings should get you where you need to be.
How are you determining it's running rich? Is it the factory intake or has that been changed? Have you made sure there are no vacuum leaks? If the carb was rebuilt, has anything been changed in it like the power valve or jets? When was a good tune up done on the engine (plugs, points, condenser, cap, rotor, timing)?
I don't mean to sound elementary, but rough running could be something other than the carb too.
Dan is definitely one to talk to. He can help you out.