I would say it depends on how fast you want to go. With the stock wing, and an OS .75 you would be good for the Sac silver class or the bay area .75 class. With a new wing and a YS 115 you would be OK for Sac Gold and bay area unlimited. The fuse can be left stock but I would suggest some strengthening mods on the tail no matter what you decide to power it with. Even if you trow away the wing and tail, thats still a great price for the fuse. I hate to think how much I spend 100% scratch building my race planes.