This is a heads up for anyone who wants to install an oil pressure gauge in their Z. To start with. When starting my Z. Oil pressure will spike over 100 psi for a few minutes, then it comes down to 38~40 psi. When I rev it up. It will go over 100 psi at around 3,500 rpms. So, if you want a gauge. Get one that goes to 150 psi. I have a SpeedHut 0 to 100 psi gauge now. I have on order, a 0 to 150 from them.
Here's the pressure sensor adapter to get.
Oil Pressure Sensor Adapter, 1/8" BSPT - Engine - Autotech Motoring