I have a MS290 that i use on my property to fell trees and cut them up for firewood. I am currently running a 18" bar that is .325 with a non safety chain. I've had the saw for probably 8 years and I recently did the porting mod to the muffler that I found online. It does feel much stronger than it did prior but i'm still looking for more. I think I'd like to run a 3/8" bar and chain and a 7 tooth sprocket or rim I'm not sure if my terminology is correct but I need come suggestions on a setup please.