I have always tried to match the motor/axle angle for the gear angles with a combination of pinion and spur angles. The C-can angle is about 16-20 deg and the smaller cobalt motors end around the 2-5 deg range.
What racing series allows a 26 ga armature in a C-can other than bracket drag racing? Any motor can be used as a play toy for the rush of it. Might be a new class: C-can group 7.