Here is some text out of the 1950 salesman’s data book along with the last page in this pdf out of the 1929-1957 Chevrolet Master Parts That should let you see what is what on this subject. The reproduction fuel tank that Jim Carter has made was off an original 1947-48 pick-up tank just like the 1947-1953 full-bodied panel, canopy & suburban tanks at IS 16 gal (aprox) as the 1 ton panel and canopy sport a 18 gal tank.