I have ordered a GP Revolver... I don't think they give me an option to add my servos to the rear, only the center... but my engine the Rossi 65 weighs in at 700g as suppose to the recommended engines at 550g or so... so I am just guessing that I will need to cut out spaces in the tail to add servos... what do I need to get to cut out neatly? or what do you guys normally use?