I think the Panel Body gas tank (under body) has a different sending unit than is used on a pick-up (with behind the seat gas tank).
I could be wrong, if the pick-up sending unit changed between '49-'54. My '54 pickup has no gas line fitting on the sending unit but my '54 Suburban has the gas line fitting going through the sender unit. Also, the pickup tank is "taller" than the Panel Body tank. One company sold me a "universal" unit for a Panel Body but it was no good because it did not have the gas line.
By the way, my old unit was "frozen" but, after finding no replacement unit, I had no choice but to try to unfreeze it. After many applications, WD-40 freed it up and it now works fine.
