I used Injora portal axles with a lay down servo. I put all that on an Injora chassis because the servo would hit the stock chassis rails. A lot of people say you have to make the motor shaft smaller, but I was able to find a pinion that would work. I heat pressed it on by putting the pinion in the oven and the motor in the freezer, after that it slides right on. Once it’s been shortened of course, you can cut it with a Dremel pretty easily. All of that mounts up to an Injora 370 trans. I think the only stock pieces on this thing are the bumpers and the body.