[SpEEdyBL]

The c40l is definately not strong enough for a monster truck. It's about the same as a feigao 380c 12l, if you are familar with the feigaos. I've heard of a c40 12s (3600kv) being run in an emaxx, and it was cut down to 7lb using lipos and went 30 mph. The 12l will have the same power as the 12s on the same cell count, they just require different gearing.

If you want 40-45 mph in a monster truck, consider more cells or lipos. 12 nimh cells just wont cut it. I mean you could, but not reliably. There is a good chance that the batteries will overheat, and the lower the voltage, the more difficult it will be to find a motor/esc that doesn't overheat as well.