VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Engine Number question

Can anyone decode this engine number CON13XXX ?

That is not an engine number.......it is a casting code.

Yes I know it is a block number. A source from Chevrolet says this:
CON CASTING MARKS
When the Chevrolet Grey Iron Foundry was created from the Saginaw Products Company, Saginaw,
Michigan, the casting marks changed from “SPC” cloverleaf to the Chevrolet Bow-tie. Further, there was no
need to source from Ferro Machine and Foundry Company, so the “FERRO” mark was dropped.
In 1929, the first incidence of the “CONV-“ mark appeared on the 6-cylinder engines. This mark appeared
on Cylinder Blocks and Heads and was repeated in 1930, 1931, etc. However, it appears that not all known
1929 castings have this mark. It is therefore an unsolved mystery [at present] as to what it represents. In
later years “GM” was also cast in.

Interesting

My 1929 Block and Head has both the CONV on it and the Bowtie

29 Block Bowtie
29 Block CONV-3


29 Head Bowtie
29 Head CONV-2

I had always heard that the CONV XXX referred to the conveyor belt number the cast part ..block, head, etc was assigned at the foundry.