I'd run 8-15 degrees of timing on a 4 pole motor. Start off with 8 and work your way up to where you like it.
I'm loving my 70mm, geared 18/46 in my Hyper 7 after a run the motor is around 90-100 and my ESC is about 20 degrees warmer than ambient. I've got a 24T sitting here that I'll try on it next.
All I ever wanted was an honest weeks pay for an honest days work.