[Serum]

Perhaps it's easier to go flightpower 4S 4900's or 5000's. With the stock setup, it's rather hard to make a dual trakpower work. A single pack would be easier. You can stack the trakpowers, but it's harder than a single pack.

With the stock setup it's almost impossible to make a balanced setup (left/right balance)

With the 3.3 they didn't put the servo's further to the front either, so that's not helping you any..