I ran the 394 today, dual port muffler with a new meteor piston and rings, its a beast, love the saw. I also ran a 390 that I dual ported, all stock, felt great also. I did a BB 365 special, but have had nothing but issues with the saw, so I can't compare it yet. It is having fuel issues, its going lean. the plight of the 365 can be seen in my topic, 365 throtle hanging up.