When I ordered the new F20 tank, I wanted to put in a new sending unit. I ordered one from Melvin's, only to find out it's back ordered for months. So I looked on here and couldn't find any one answer about a compatible unit. So I ordered a 71-73 Mustang sending unit to see how they compare. The bends on the tubing in the tank are the same, same float set up, and the outside is the same. I then took ohm readings. The unit I received was 8.4 to 78.8 ohms. That should be close enough to work in these cars. For about half the price.