I agree that 3s may be too much for the 6L. The bad thing about that motor is that it's kv doesn't match up with lipo very well. 3s is too much, and 2s is too little. 8 NiMh cells at 9.6 volts would probably be ideal.
With that said, I run a 12s with 12 NiHm cells or 4s Li-ion, and it is FAST! Over 50 mph with no overheating so far.
Ya I see what your saying. I guess I can run it on 8 cells im going to go lipo but ill still have my gp cells to run in this. Thanks guys I'll be ordering up the 6l soon then.