you could always put a smaller sproket on the rear which will give you the same effect as putting a larger front sproket on...
usually 3teeth off the rear sproket is like adding 1tooth to the front...
the blasters are slightly undergeared from the factory which is why everyone runs a 14/40 gearset because the blaster has enought power even stock to top out that gearset but just barely...which is what you want..