(1) "this guess came from information found at various reference sources on the Internet." I have put the information (sometimes conflicting information from different Internet sources)
into this table. (2) This sounds good to me because I've seen this decoded in this manner on this site many times since 2001.
(3)
Catalog of Chevy Truck ID Numbers, 1946-1972. This used to cost $20 but now sells for about $80 (why?). The code shown in the original post does not exactly match the information in the Catalog (so I wrote "might" above).
(4) This guess is based on the number 55 being found in so many places on 10 micron's block.
(5) This is based on information posted on this site since 2001, and found in 1954-1963 Chevrolet Truck Shop manuals, and seen when comparing heads and rocker arms assemblies and oil connections over the years that I have worked on these engines.
Nonetheless, any of the above information might be wrong (as stated in my post). My hope is that any mistakes will be quickly corrected by others.
I guess a simple reply about what years' heads would work with 10 micron's block would have been to check the block-to-head bolt pattern with the
head bolt patterns on this page. That information came from 1940-1962 Chevrolet Truck Shop Manuals.
I wish I had information for 29-36 head-bolt patterns, bolt-tightening sequences, etc - you never know when someone might need it.
Tim