i use a stock silver can 540 motor and it is way fast enough and has more then enough power to have a ton of fun.
i would recommend printing the small bevel gears, pinion gear, and wheel axles from taulman 910 nylon instead of PLA it will make the drive- line heat and shock resistant. there are many upgrades for the truck from other authors that will increase the trucks durability and performance.
i also recommend some type of heat break for the motor to reduce heat transfer to the PLA as it will melt.
a tamiya phonetic motor spacer is a good way to stop heat transfer.
I have melted the pinion gear which is why i went with 910 nylon as it absorbs heat no problem.
my trucks have tons of upgrades from thingiverse and also home brew to increase performance.