I am running the stock muffler right now but just bought a Pro Circuit T-4 from a rider off of TT. My current set up is an OCEMN 4th clip from top, 48 pilot(stock), 170 main and variable from 1.25 - 1.75 turns out on the FS(Thanks to Kouba link) and 1 second squirt time on the AP.
What are you riders using for the T-4? My altitude is from 1k- 4.5k ft roughly and right now the temps average 68-75 deg F. Thanks for your input.
Unit, I think you will not need to make a change, except maybe on the mixture screw. I am running the same set up as you, except (#5). I also have my crankcase breather rerouted. I think you will really like the T-4, I do. Good LucK.
I'm running almost the same set-up as you and Strick. I running a little leaner on the main but other than that your set-up should work good. Probly want the fuel screw about 1 turn out at your temp and elevation.