I'd run 2 machine wound Atlas mod motors. The two of them wouldn't last 2 months of about every other week of racing. The wire would just got darken causing a motor to overheat. I lathed them every 6 batts.
I ran it on my Xray, with a final ratio of 8.94 - the motor would scream about 3/4th on the 110 feet straight line. Would bump a tooth up on the pinion help the motor cool a bit ?