this is something I have been interested in since the day I moved to a small grass strip with trees on both ends.I don't think a 150hp convertion is the way to go all you need is about 25hp to make the 150c climb out with two people and full fuel and not feel like you need to lift your feet to clear the trees.
The performance you are looking for is available for a fairly inexpensive price, its called Vortex Generators, special wing tips, flap and aileron gap seals, a Sensenich prop, and 28 degree timing.
Charles
