Welcome to Stovebolt.com, Matthew
My interest/knowledge is also in 1947-55 Advance-Design Chevrolet trucks.
Well, there is a lot to learn about stove bolt six engines, typically thought of as the 1929-1963 216, early-235, late 235, and 261 straight six engines.
The internals changed considerably over this time period.
Major changes in 1937 and in 1953-1955.
Check the engine section in the Tech Tips (here - look for link above).
This Spotting Guide is in the Tech Tips section of Stovebolt.comhttp://www.1954advance-design.com/Web%20images/Clymer/slides/Stove-Bolt.htmlhttp://www.1954advance-design.com/Stovebolt-engine/index.html