So I have a Nero w diff brain and I wouldn't recommend going below 4s because the truck is too heavy for one 3s on a 2000kv. You'll only have a max speed of 25 on a perfect surface, probably lost ability to wheelie, and most importantly, if you go off a jump you will definitely not have the wheel speed necessary to make any in air adjustments at all. On 4s in air adjustment is significantly more delayed than on 6s. So I can just imagine that on 3s it basically just won't be there. So you'll end up spending a lot of money on a truck with none of its intended benefits. If you just don't want to have to buy a bunch of expensive batteries you can run on a single 4s pack and plug one side of your series adaptor.