I think there is a possibility that the sending unit could be the same for 65-68. I've read on this forum that the frames for 65-68 are the same and I've seen suspension parts listed for these years under 1 part number. You would have to research it. Have you pulled your sender to look at it? My 66 Mustang had a bad one that had a visible bad spot in the coil once the cover was removed, not repairable. But, I took apart one from a friends Mustang II and discovered that only one end where the coil attached was loose. I was able to fix it and it continues to work great. Worth a shot.