[MetalMan]

That wouldn't be a good idea either. That is, unless you feel like spending $4-500 on a controller! In a smaller 1/10, 7.4v can get you over 40mph easily, with a low amp draw (~50amps). The best thing to do will always be to put batteries in series since with higher voltage efficiency also rises. Efficiency factors into the motor output formula: amps x volts x efficiency = watts.

Back to the original subject. The wires are meant to handle 60amps continuously, but much more than that, and the resistance of the wire will cause undesirable voltage drop, and at too high of an amp, the resistance can cause the wire to heat up too much. But you definately be fine for bursts to 120amps, but not for extended periods.