They did drill a new hole. I was hoping that they could tie into the one that I already had. The nice thing about having it hooked up to the attitude is that you can set your egts at a certain point and then when the truck reaches that temp it will cut back enough to leave it at that temp so you can leave it WOT and not go above where you set it. I believe the it would still work if you didn't have it hooked up though. The display is real easy to read.