Does anyone know what the "B" stamped on the decks of my 455 mean if anything. they are located between the water ports behind cylinder #1 and the same location on the opposite bank of cylinders. The block is a 1973 455, but don't know what it came out of.

 

The letter code as stamped indicates the factory finished cylinder bore size so that the correct matching piston size is picked for use in that/those cylinder(s) during assembly.

 

interesting. I assume that accounted for the wear on the machine parts over the production run.

 

Nothing to do with wear, It was all about these engines being part of mass production. And the WIDE varied tolerances that were acceptable.

 

From the 1972 CSM. 73 is probably similar.

 

so did they measure the bore after cutting it and could there be multiple sizes on the same block? Only found one B on each side.
doesn't really matter since the block has been bored .030 over

 

I think they used the same mill on finishing all 8, so they would be the same, nominally.