fragile spur gears???

[brijar]

I run an E-Maxx with a 9L and a 9920 and the motor gets about 140°F, usually a little less, on 16/66 doing mostly high speed street running with 14 GP3300's. The ESC is usually less than or equal to 120°F. I run stock tires though and have a fairly lightweight truck with barely any aluminum at all. I am running 16/72 because it's about 104°F outside right now:036::013::026:. I am fairly happy with the speed, but could someone let me know if I am seriously over or undergeared? This seems to be the motor/ESC's happy gearing, but I would like the motor to run a bit cooler. I haven't stripped any gears with my setup, though my tires are so old they can't get enough traction to lift the front tires up unless I floor-it on my cement driveway.
Just thought I'd let ya know as I run a similar setup.

Brijar!!!