seems to me that the rcs 140 or 180 would be too small for a pica 1/5 scale mustang. i have a g-62 for the one i have under way. i would look at the world gs but only with at least the 180, which is 30cc as i recall- but i would really think that you want a zdz40 or above for even the world gs. i would not be happy with a warbird that didn't fly strong.