Trainer's typically have larger wingspans than sport planes for the same size engine displacement (and combat planes like I fly, are even bigger, 64-72" wings with .15 size engines, but I digress). I'd stick with a recommended engine, putting that much power and weight in the LT-25 will take away some of the desired flying qualities. The LT-40 is actually a very nice flying plane, well liked at my club, several experienced pilots here have them for goofing off with.