As far as I can remember,GP doesnt have tri stock in all corners, I add some,even hard wood( I cut them myself from square stock),use epoxy. The 4-strokers and bigger 2 strokes(1.08 & up)do vibrate more and the firewall will probably need "beefing up". I also thin some epoxy with Isopropyl and seal all the exposed wood and glue joints from the oil slick. The glue used in most ARFs does not hold up well with oil,its softens and peels off in a short time with constant exposure to oil. I took the wife with me to show her some hovering,harriers,ect..,she's never seen me do that type of flying,she actually yawned after some DOD hovering!!!! I mean,here we are,going beyond mere flight, into the Third dimension,and she yawned and stated she liked another guys plane! All he was doing was straight & level,maybe a loop,she said she liked the faster flying!!! Guess I should get a jet!(actually, it would be cheaper than another wife),