Can i put a bigger motor in. Since i bought an 1/8 th monster truck with a .25 engine. The mega force is just too slow now.. Thanks for your help

Mabey you can put something like a OS CV-R in it and go up a few teeth on the cluch bell...

Some people have put weak .21s in with some minor home made mods with no claimed problems from the tranny.
I have a megaforce too, is it sluggish for you?

picco15 is good too i had it on my terracrusher and the guy i traded with said it can haul the big tc

thanks for your suggestions. i will try the picco and 21 with smaller tooth gears on it.