i have gutted my apache and done almost every upgrade to it(flex shaft, rudder, remove the part of the hull that the old stuffing tube went in/ to make the center of the hull flat, battery placement in either sponson.

but i still have stock esc and i run a traxxas titan 550 23 turn on 12 cells on a plastic octura y534. it works fine but i want some more speed. i am on a tight budget and am thinking a graupner speed 600 will give me a little more speed. am i right or is there a better option?