Bad idea for a couple of reasons. The first is that it will rip it apart and make an unsafe model anyway. the second issue would be that you would have to jack the landimg gear way up to get the needed prop clearance(look silly) and the third you would have to add so much weight in the mod like the extra weight of the engine, necessary weight in the tail to balance it out, added fuel capacity to get a decent flight that the plane would be so sluggish and heavy with a huge wing loading that it would be a real turd to fly, not to mention not fun!, and lets not forget that the servos would need some beefing up do deal with the extra load! I would suggest the same as the last post, pipe it or make a slightly larger engine selection, a .60 while not out of the question would be on the high don't go any highr side. Good luck!

Chris