There's a simple solution to your problem that Ford came up with.
My daily driver is a Tickford Pursuit 250 ute. It runs the last of the windsor motors that was factory stroked to 5.6L. It's a bit of a factroy hotrod.
As part of the Tickford package thay came with a different dash cluster that includes an
oil pressure gauge. Cool! My
Oil pressure was always good and the gauge rock solid.
The sender started leaking so I went on the hunt for a replacement. After searching through parts lists and shelling out $50 on a new sender from Ford I had the ute up on the hoist and replaced it. After firing it up I had no
oil pressure. WTF!
After further investigation I found that part way through the model run Ford had replaced the pressure sender with a pressure switch. No wonder the bloody gauge on the dash was always so solid. Turns out customers had been complaining about fluctuating oil pressure so they found a way to solve the problem.
Cheers