[suicideneil]

I like my 5.5mm gold bullet connectors, but there is a fairly recent thread with pros, cons and alternatives to every connector going- might be worth seeking it out.

On the gearing question, you can start off with fairly conservative, then work your way up until temps start to climb:

51/14 = 42mph
51/16 = 48mph
51/18 = 54mph

My only concern would be that a small spur gear may not mate up with certain small-ish pinions, but instead the motor will hit the tranny before they can mesh/ mate up properly. Cant really answer that myself as I have a smaller diameter motor (36mm vs 39mm for the smooth can neus) and 32p gearing..