IMHO, the stock oil pressure gauge is junk, marginal at best, too highly damped, and often inaccurate. I prefer a mechanical gauge. I'd tee the port where the oil light sender lives, and use the light and a mechanical gauge. The inclinometer dances when the damping oil inside leaks out. There's a cast bullseye thermal expansion diaphragm in the back of the gauge that cracks over time and lets the glycerin out, but it can be repaired with something like clear rtv that stays flexible, and then you can drill a small hole in the top and refill with compass fluid, sealing the hole with more flexi stuff. If you want another gauge in there, like atf temp, there are ball in curved tube inclinometers available from many OR stores that do a very good job. You need two, one mounted fore/aft, and one side to side.