Well if its a newer xl it should come with the 2.4 ghz! Id get a ercm pipe. Waterproof servos. Change out the k5.9 if you want. Shim the diffs an trans, an mod the 3 speed like i did so its bullet proof. I'm still running the K5.9 in one of mine, an not a single problem yet. Been a good mill for me.