I just fitted my 066 red light up with a 20" bar and 50% worn full chisel chain, the same as is on the 044
I sharpened them both with the same 13/64th file to be razor sharp
Set all the rakers to .025 on both
Both saws are running a 7 pin sprocket.
Both saws have near identical dual port muffler mods
Both saws have had a small amount of port tidy up with no timing mods.
The 066 is running OEM piston, rings and gasket with .020 squish, the 044 has an aftermarket piston and had its gasket removed and .012 sanded from the base to drop squish to 0.020, so its been dropped about .032
The 066 has 160 psi, the 044 has 162psi
I dont know if I can pick which one will win, having used both.
The 066 has more power/torque but the 044 has more chain speed with the higher RPM.
I am picking they will run close with the 20" bar but the 066 will shine with 30"+ bolted on and buried tip deep in hardwood. Problem is I dont have any big timber to try it in at the moment.