Fuel tank sending unit rebuild service

First of all, you have an 18 gallon tank in name only. If you put 15 gallons in the tank, you were definitely running on EMPTY. I put 3 gallons in a completely empty 18-gallon Spectra tank, and the float did not move and the suction tube was not covered. Just after 3 gallons, the float starts to move and the suction tube starts to get submerged.
Interesting. I don't daily drive the car so it's no big deal to put fresh gas in every time I drive, it seems to burn a half a tank every time I take it out. I'd like to convert to EFI so I'm looking into ways to convert the tank that I have to an in-tank pump with a return line system. Aeromotive is five minutes from my work, so I'm thinking about stopping by and talking to them to get their thoughts. They make a tank for the 70+ A bodies but not the earlier ones.