I would call your parts house & have them pull the # for the kit listed for a '66 383 carter BBD 2bbl & see the years it covers but I think the odds are that there is quite a spread there & that a kit for a '66 would cover your carb even if it ain't original (& I'm thinking that it is). You could just install the new needle/seat out of the kit (have the top off) & they interchange no matter what year) then recheck/set the float level as needed (might be 1/4" iirc), the white sheet (& your buddy) will help you. clean the carb base and the manifold base and a new base gasket (will be in the carb kit) & reinstall the carb/lines/hoses/linkage etc. I like to lube the top bowl screws that secure the top to the main carb body (actually any screws that go into aluminum). open the throttle all the way then spray the carb throat with starting fluid then shut the throttle & crank it. EDIT the needle/seat assy is brass so "reasonably" tight on that