Jaybee,
A reciever pack will let you have the full speed and torque of the servo. That is the main reason why I use one in stock. btw, I have a ko 949 servo in mine, and I don't have a $100 to have less than 100% performance
.
I would open up the casing on the ko and see if you stripped a gear. If you stripped a gear, the replacement is far cheaper than a new servo.