Thanks for the reply. I'm pretty sure the base GT has oil an pressure and vacuum display as you scroll through the different gauge features. Wish there was a way to know for sure! I'm guessing that there should be a wiring harness behind the dash. I need to reread this thread! LOL!
Glad to hear they didn't give you a hard time. Sounds like you've got a great tech and dealership working on your Mustang. Glad it's working out in your favor!