Engine number 346 flathead

[wurzen-caddy]

hello around here.  can someone explain the difference between a 1937-1941 and a 1942-1948 346 flathead?  I just got really excited about mine and would like to rebuild it from scratch.  unfortunately i don't know which year my engine was built.  my caddi is 1941, but my engine should be younger, it already has the engine number on the front right above the water pump.  I think the number only appeared on the front right from 1942, 1937-1941 it was on the back left.  feel free to improve me if i'm wrong?  I just don't know which parts to take?  maybe someone knows the exact year of construction for my engine number?  5400144

[harry s]

Looks like your engine came from a 1946 61 Series.      Harry