Your last post gives good info.....I've been flying gas for a short time now.....about a year or so......10 CC gas equals .60 2 stroke glow.....
But a plane weighing in at 15 Lbs would need a 40-45 CC gasser.......ask lots of questions because gas is different than glow in the tank set up.....plus I recommend an optic kill switch.......no direct wire feed from ignition to system...and kills the engine in case of a loss of power, and a very nice way for you to kill ignition when you want to open the choke or prime......
One more word of caution......everyone in my circle of friends has had a loss of confidence including me, when going to gas......go slow get the motor broke in with at least 3 gallons of break in gas before you start to get wild......your confidence comes back...you know your hooked when a 160 sized glow engine sounds weak