Carburation setting ideas please??? Moving to a quieter exhaust for track day

[slabsideB12Kent]

I had my GSXR 7/12 Dyno'd at Bob Farnham years ago with a Micron spring attached "Race system" using standard 1200 Bandit carburetors with foam filters. Came out loud running 125 rwhp

I want to take the bike around Brands Hatch but it fails the 102 Db reading test by alot. I have no option but to convert to another Micron system I have which is smaller in diameter, bolts at the manifold and has a baffle in the end of the downpipes, then including a "road legal" end can that I've repacked. 

I think this more restrictive exhaust will make the bike run rich? 

When I got the bike back from the dyno years ago I had issues with lean conditions when I opened the throttle slightly so they recommended I raise the needle. I'm thinking that once I fit the more restrictive exhaust I should probably at least lower the needle back one or even two stops and adjust the pilot screw?

I've rebuilt the carbs but didn't record the jet sizes, should I expect to change the jet size?

Opinions gratefully received, thanks