how hard is to install a tranny temp guage?

 

I've been wondering that also. A friend of mine put one on his Camaro but that's completly dfferent.

 

It's not hard, next time you do a trans oil change, you can poke a hole in the side of the pan for the sender.
For aftermarket/aluminum pans, drill and tap the side of the pan for the sender. I talked to quite a few trans shops and they all recommend mounting the sender in the pan.