The speed governor in a thm350 is a centrifugal device with weights and springs altering this device is tricky .Try the after market.

A governor in gasoline engines is a device to control the amount of fuel available in order to maintain a predetermined RPM for the engine.

A load limiting governor is a device that regulates and measures the amount of fuel that enters the engine. The load limiting governor will ensure that there is not more than enough that will enter the engine.

The governor is not a mechanical device that can be removed or disabled. The governor is programmed into the car's ECM. You must interface the computer and disable it, if possible. I'm not sure that it is.

Governor