I did the engine mount move and the servos also using sub c cell pack im only running a 91 fs on it so it is a minumal engine but pulls it scale like as far as cg on this kit it was not where it shows on the plans it had to be moved almost a full inch forward when i balanced it to the plans it flew very tailheavy and almost lost it lucky the landing only resulted in minor damage and nylon bolts sheared off the way they should .I wrote Dynaflite a letter about how they should modify the plans but no response.but she flies beatiful now .I was just offering another option to balance out his aircraft also if you put weight in the cowl try to keep it low as weight on top will posibly cause snaprolls.