Agreed with wjcalhoun. I embed a piece of basswood in my tail section. It's about 3/8 x 3/8 x 3". Requires digging out a hole, and you need to be careful not to dig TOO deep, or you'll go straight through to open space. Need to leave a box of foam to epoxy the basswood too. Once dry you file it down (if needed), cover with trim and screw the third party gear in. Unlike the production rear gear, this mount will never fail. (it does add some weight to the tail, but that seems more than offset by the larger engines most of us are using).