has anyone here installed a damn mechanical oil pressure gauge on their 4.0? I have never done it and people just keep saying..... "Well just go buy a cheap one and throw it on buddy, and see what is wrong with your oil pressure." Do you just go pick one off the shelf and it fits universally into the sending unit hole? I'm getting just a little bit frustrated with this. Some people "T" off of the hole and run both gauges, how does this work? where do you get a "T" for the hole? etc. etc. etc.