An OEM panel truck tank is 31 inches in length, 11 inches wide, 13 inches deep. In theory, this is a 19 gallon tank. This is in keeping with claims of GM for the time period and matches up with a "behind-the-seat" tank truck. Usually you can only get in about 16 to 17 gallons before slosh out becomes a problem.
How does this compare to yours? Is yours OEM or a gray market replicate tank?
For trivia, I have seen a lot of these where some stringless yo-yo has connected the fuel line to the drain plug front bottom edge. This plug is about 2 inches or so off the bottom. Limits tank capacity to about 15 gallons unless you are always driving down a steep hill. Going back up this hill becomes problematic.
Billyray
