Hy chopperguy16, I know they changed the sender and gauge from a 0 - 30 ohms to a 0 - 90 ohms somewhere in the 1960s. Classic Industries website lists 1964 and older as 0-30 ohms, and 1966 and newer as 0-90 ohms (I guess the 1965 vehicles didn't have fuel gauges). I did try looking in the parts book to pin down the year they changed, but with all the different models, each with their own sender I just got a headache, hope that info helps some.
