I bought a reproduction oil pressure sender p/n 2495222 (80 psi)from Bill Rolik for my 440 Superbird, but noticed the dash gauge was reading lower than the actual oil pressure (as measured with a mechanical gauge)
I took it off to check the calibration and found it to be way off

At 0 psi, the sender was open circuit (it should have been ~74 ohms)
The sender remained open circuit until 14 psi.
At 80 psi, the resistance was 15.3 ohms instead of the the expected ~10 ohms.
( I had my gauges restored and calibrated by Redline and had an electronic voltage regulator installed)
Bill was kind enough to send me another one, but it turned out to be the same.
Instead of returning them for a refund (which Bill offered to do) , I decided to cut it open.
The following are some photos of the guts as compared to a stock Mopar unit. It is a totally different design and the resitance winding is not designed correctly to interface with the Mopar gauges. This seems to be similar to the repro fuel tank level senders that are not wound correctly.
Looks like everyone is using the same company in China to make these repro's.
This is a photo of the guts of the repro. The brass wiper is not making any contact with the windings at 0 psi.

This is a photo at 80 psi.

This is the original Mopar unit at 0 psi.

This is the original at 80 psi

I bought one last year or the year before from Bill, it's still in one of my box's of things to use when car is hopefully done - thanks for the explanation and the pics