I'm not an expert (If I touch your motor it loses 5 watts on the dyno), but from what I see of the guys who are fast, higher amp draw is better. The caveat is that they have already reamed the bushings, set the shimming, aligned the hoods, etc. If you just throw your motor on at 3v and go "wow it does 9 amps", it may not mean much. If you have already prepared it, and it is done right, it is a good RELATIVE gauge.