Well my "T" broke while driving last night and I had to JB weld my thermostat housing where the cluster sender sits shut to get me home. I'm not sure if it was causing some really odd readings on the dummy gauge or if my Autometer gauge was off, but this leads me to think that both senders MUST be in the housing to get accurate readings. My question: Would it be fine for me to drill and tap the little hole that sits before the thermostat that has an allen head cap in it? I want to stick my Autometer sender there and put the dummy sender back to stock. Also, has anybody noticed a real difference in readings between their aftermarket gauge and the stock one?

check this link it has a pic of where to put your sender.
http://forums.2gnt.com/dcboard.php?az=show_topic&forum=4&topic_id=43977&mesg_id=43977&page=2

I never noticed that. Thanks. What type of plug am I looking for?