This may be old news for some but informational to others. That is now there are many ARF's flooding the market. Thing to keep in mind is a fair amount of them already have "right thrust" built into the firewall. Simple way to tell is to lay the fuselage down on the floor, stand over it and look straight down onto the firewall. If the firewall is at an angle, then thats one less thing to worry about

Your plane can also be built with too much right thrust.
My Extra had 3.5 dgrees out of the box.
I had to add left thrust to get it to 2 degrees

Another way to tell if your plane has built in right thrust is by standing up the fuselage with the firewall flat against the floor. If the fuselage is tilting slightly to the right, then the firewall has built in right thrust. Yep, some ARF's have too much right thrust. One of them is my GSP Spitfire.