A muffler mod would be a good start - just about every new saw will see some degree of benefit from that.
I agree with Lukem. Don't forget to retune afterwards. If the new 311 muff is like the new pro saw cans? It should be a piece of cake. But if it's like the old 290/310/390 series? It may be a little more tedious.
I have worked on 2 of those. I wouldnt even muffler mod them (yeah yeah I know but IMO not needed on this saw). They ran perfect IMO for the firewood cutter.
Yeah but every now and then I will fell a hickory or two and would like a little more power to cut at those big trunks. Never modded a muffler before but have ported intakes on cars. Might try it.