1982 Kz1k LTD Fuel sender doesnt fit

I think the tank is from an 80-81, the fuel sender doesn't fit the new tank, and the sender already in the replacement tank doesn't connect to my harness. Any ideas? Or am I off to find a 1982 tank...?

this is the only pic i have of the new tank right now

- I'm 80 miles away, so I'll try to get someone there to shoot a pic of the underside of the tank. Thanks!