Oil gauge swap on an 81 Spider

[Roycape]

Hi all - I have a oil gauge from a pre-1977 Spider that I will be swapping out with the clock on my 81 Spider. I checked the archives and got instructions on doing the switch. However I don't have an oil pressure sending unit so my question is what oil pressure sending unit can I use besides the ones offered by the regular Fiat vendors or one from an original pre 77 Spider. Can I use any aftermarket sending units with the Fiat oil gauge? Will this cause erratic or erroneous readings? I presume that it will have to have the right fitting or adapter...I think it is M14 x1.5.
Many thanks.

[So Cal Mark]

you need a sending unit with the correct resistance for the gauge you have

[vandor]

>what oil pressure sending unit can I use besides the ones offered by the regular Fiat vendors or one from an original pre 77 Spider.

None that I know of. I know Bosch ones work the opposite way from the Italian ones.

[Roycape]

Thanks a lot for the responses guys. I will source the correct oil pressure sending unit I have for the pre 77 gauge since I want to keep that gauge to match the others in the dash.