39 and 40 models used the same tank and location as the 41-46 models. In 47 chevy and GMC took em out of the cab and put em under the bed. In 1949 they went back in the cab behind the seat and stayed there untill 1972. In 1973 they put em between under the bed outside the frame... those were the ones that were in the news for exploding on side impact.
Kind of scarry if you think about it... most stovebolters are sitting on a bomb. EEK!
