Yeah, the HW 60amp won't do it. I had one on a Slash 4wd and with the Vxl 3500, it would just barely handle it on 3S. The heat on the esc would just creep up and up. Looking through Castle specs for that esc, 5700Kv is just barely in the 3S limits, and that's only with a light 4wd truck around max 4lbs. 5700Kv would be ideal for a 2wd. But for a heavier 4wd, that's really pushing it. http://www.castlecreations.com/suppo...5-0130-01L.pdf