Kevin,
See my post on page 1 of this thread. Your image is from the 1950 Master Parts List. This is the available block (in 1950) to replace one from a 1937 engine. See the NOTE below in your image which means one even has to replace some parts to make it work. This listing does not mean that is the block casting number that came with the engine when new in 1937.
Regards,
Kent

1937 Chevy 1/2 ton
1942 Chevy 1/2 ton
1947 Diamond T Model 509
1951 Chevy 1/2 ton
1950 Chevy COE Model 5700 ~ "Barney" ~ And more pix