Glen, you are correct, except I think you may have the two pieces backward. I believe it's the tops that are the same, and not the bottom. In the first picture, the one on the box is a '36, and the other is a '37-'38. In the second picture you can see them sitting on top of each other. The curves on the bottom pieces don't match.
One of these days I'll get around to putting an ad on here to sell the '37-'38
RB:
I based the reply on the information in the 1929-1942 Master Parts Price List, group 16.010 that shows part number 602132 for the upper frame for a 1936 low cab and part number 602498 for 1937 and 1938; and group 16.015 part number 602131 for the bottom frame for 1936-1938.
The 1936 Low Roof cab is slightly lower than the 1937-1938 which is probably why it is so popular with the customizers-street rodders, as there is no need to chop the roof as chopping a roof is a lot of work.
Back then maybe GM figured the 1936 Low Roof was too low so they retooled the roof panel for 1937 and 1938. Looking at group 16.585 there is a roof panel for the 1936 Low Cab listed as number 592514, and 1937 and 1938 is number 597902.
Glen
