Ok, for 2000-01 gt Windsor engine guys, your oil pressure gauge install is going to be slightly different then the Romeo's. Like WmBurns stated there is no extra place on the side for an easier install. The battery cable/starter cable is in the way, so a T plus an extension is out the answer if don't remove this cable. If you like me and want everything functioning, your going to have to T it off.
Every pipe adapter needed is a 1/4 inch npt, Female and male, make sure you use the white plumbers tape on the threads, w/o it leaks will occur. You will need, one elbow, one side female one side male, coming from the place where the oil switch was, comin from the elbow, one straight pipe fitting both sides are male, then the T fitting, all sides female, only then you will be able to clear the cable and oil filter to tighten, your sender must be pointed torwards the ground, no other way to fit it in there, your switch pointed torwards the left fender. Your oil switch wire is going to be stretched to its maxium length when you connect it again. You can use, if you must1/4x1 1/2 inch npt but, w/all that oil its going to be hard to thread but, it will go, the threading is tapered, so it will accept both fittings. I went threw the passenger side firewall, didn't feel like fiddling w/my clutch cable for just a wire from my electrical sender. Out of all the gauges, this is the toughest, IMO. There is a pipe going to somewhere, i havn't yet figured it out but, its right by where my oil sender should be, you will want to use some plastic ties to tie it to the the pipe/tube. The fittings are going to be a little lose, no matter how hard you try to tighten, b/c of the oil, so this step is neccesary.