I just sold mine, theres a thread somewhere around here still, DONT DO IT!!!! You will spend an hour (once you get good at it) tuning the engines together, then after 2 tanks, which go quick, one is dragging again, I admit it was the funnest RC I have ever been anywhere around when it was dialed in perfect, BUT I was ALWAYS tuning, and tuning, and tuning just for mabye 20 min. of run time then back to tuning. you get crazy torque, alot more than you can get from a bigger engine but unless you are doing pulls, it is not worth it at all.