Kyosho 540 size motor replacement?
 

I have an old Kyosho Big Brute and looking for a replacement for the LeMans 05 Stock motor that came with the truck. Does anyone know anything about this motor, is it worth replacing and if so with what? I know the size of it is considerably larger than the standard motors used now. Will a P2K2 or something similar fit in it and power it? How many turns should I look for if I am just going to be screwing around in the backyard and jumping (a little speed would be nice too)?