adding a transmission temp gauge on P30 chassis

Something else to consider is if you have electric fans in front of the radiator you can hook up a manual switch (with a on light) so you can add extra cooling. The fans are automatic but a switch gives you extra control.
The fans have a relay and you can wire into the control side.
I used this switch for faster cool down when coming off of the interstate before shutting down. The temperatures can really build in a hot engine that is shut down too soon.