I upgraded a 30 to a 50 recently, the upgrade kit came with some instructions that said some people prefer to use the short boom and blades and even the 30 gear ratios! According to them i just paid 99$ for a motor mount! LOL!
Fortunatly when i opened the box for my new OS 50, the instructions didn't say something stupid like "some people prefer to use the TT36"
Its a good thing the folks doing the marketing and instructions are not the folks doing the design. Good heli.