I'm in the process of building my 7y.o. son a Slash 4x4 MT. It's done, Trencher's on 3.2" Desperado's, ProLine arms, MIP's f/r, upgraded shocks, PL Silverado body. Right now, stock Velineon setup with 11 tooth pinion on 54 spur. It just doesn't get the speeds like he did when completely stock and he wants it "faster". Even cogs pretty bad, might be having issues sooner than later with his setup right now. He's actually a very good driver, I've broke more than he has! Looking into getting a bigger, more powerful setup for him. He will only be running 2 or 3s max. Has to be waterproof, want an esc/motor combo that will run cool, something he can just put battery after battery in it and not worry about overheating. There are so much out there, I'd like to get an idea of what others here have used or know about that would fit this criteria. Thanks.