Just an update- I bought a fan and Castle programmer. I moved the timing in the 5700 down from stock 10* to 7* and added punch control of 50%.
The esc now has good temps after a full battery run 119*, the motor will get very warm 158* but that's running a pretty aggressive gearing of 21/86.

This motor is made for stadium trucks and 1/16 scale and buggies under 5lb.
After talking to castle I ordered a 3800 and ran it with the same esc with a 23t gear, it equals the 5700 but has allot more torque.