Clee,
Seems that most times the sending units are specific to the brand of gauge. The OE senders won’t work with after market gauges, esp the oil pressure. Fuel senders have a wide range of ohms depending on the donor. You could check the sender with an ohm meter and see if it matches the input required by your gauge, (if you can find out the range of the gauge.)
Have you tried the teleflex web site for the required input range?