Cannot find correct coolant temp sending unit

[tucsonjwt]

My 83 C20 454 needs a new coolant temp sending unit. I have been trying to get an OEM replacement but I keep getting the wrong one sent to me.

The correct part is AC Delco 213-4793/ GM 88865046. This should be a 3/8" thread but the part inside is always a 5/8" thread. AC Delco customer service is no help. Nobody will actually check the thread size prior to shipment, and no dealers stock this part.

I want to stay with an OEM part because of existing accuracy issues, but cannot find even a correct aftermarket part.

This factory sending unit in my Goodwrench engine has a 56 series style electrical connector. The Delco replacement part listed has a typical spade connector.

Does anyone have any ideas about where I can get the correct part?