It looks like the first three digits on the Engine Serial Number is "236". On many GMC engines, the first three digits is the engine displacement.
236 GMC Engine GMC also developed an OHV/pushrod engine in 1939. The 236-cubic-inch (3.9 L) 236 was produced through 1942. This is a low-deck engine. The bore was 3.625 inches (92.1 mm).
thanks,would you know if these engines were the babbited bearing engine or insert bearings and are they any good ???,its seems to run great,has a few oil leaks, would like to find out what rpm they are comfortable at
All GMC engines used insert bearings. Low deck refers to the shorter distance from pan rail to head gasket on engines with shorter stroke. More GMC data on my site here: http://victorylibrary.com/mopar/m-table-c.htm#GMC