New exhaust.

Hey guys, throwing out the line here for some info. Im looking to put a 4 into1 exhaust system on my 1979 honda cb650. The name of the game is weight reduction and simplicity so having that enormous stock air box/mud guards gotta go right? So I was thinking getting rid of the stock air box and replacing with some pods or stacks not sure yet, and install a 4 into 1 system. So Im guessing im going to need to do some carb work/ re-jetting? Anyone had a similar scenario. All input welcomed and appreciated.

Change one thing at a time. Get it running nice, then change one more thing, rinse repeat...;