Can I install a 925mg gear set in my 625mg servo to get more speed out of it?

I know you can swap out gear sets from 625 and 645. Also 925 and 945 to make servos high speed or high torque but i dont think you can swap 625 gears with 925 gears.

No the difference is also in the motor as the 6xx series is only 3 pole, while the 9xx series is 5 pole.

Thanks for the replies guys. It doesn't matter now anyway since the servo quit on me in Friday's qualifying. I had to buy a new servo for the main and will be sending this one in for warranty.

The 9 series servos hare coreless motors.