Toomey makes a good product but are a bunch of idiots when it comes to jetting.
You are correct, a new head and domes won't require a jetting change.
But your 2:1 sure will.
I run T5s, 2:1 and Boyesen Reeds. I am jetted at 370 mains, 30 pilots and use Toomey needles on the 4th clip position from the top.
I have a cool head with 20cc domes in it. I run 50/50 race/premium gas.
My bike runs perfect.
My plugs are a tad rich, but rather that than a tad lean.
I run at Glamis so about 500' elevation.
If I were you, I would start at 350 or 340s and see how it does.
Check your plugs, do a WOT test.
Increase your pilot size to at least a 27.5.