Stock spec motor + on boost = fail??
 

Can I run stock spec motor (10.5T) on boosted esc setting for 2wd off road?

will that lead to failure?

Yes you can, it's what I do.

Nice and smooth on the infield and then a good turn of speed down the straight.

You can boost too much and destroy the motor.
But then you can do that with any motor.

Just watch the temperatures.

Stock spec only means there is a rotor inside that fits in spec class rules. Touring cars for example mainly use 13.5 stock spec but you boost them with ESC settings if allowed or blinky if not. I use a reedy 13.5 with an Orca VX3 set to full turbo timing and 50%ish boost on a small track and the motor only just gets warm, any more is undriveable (I could run it slower and probably lap quicker but I like it fast on the straight!!)