Letter Stamps on Block

[dekeeb]

While cleaning off the gasket residue off the block where the oil pan mounts I encountered letters stamped into the block. Any ideas on why they are there and their meaning? You'll note there are a series of capitol letters stamped across the entire lower side of the block if you enlarge the photo. The letters are stamped A A AA B B BB

 

[ndnile]

I know on WW2 Willys jeeps the top of the block was stamped by each cylinder with either an A, B, or C to denote if it was manufactured with a slightly undersized, spot-on, or slightly oversized to spec bore. Pistons were also marked with A, B, or C and they were matched up as expected during assembly.

I wonder if these are similar markings for your four bearing journals and end caps.

 

[Joe B]

Are the matching letter designators stamped on your bearing caps?

 

[dekeeb]

Are the matching letter designators stamped on your bearing caps?

There are no similar stamps on the bearing caps, that was my first thought as well but that didn't seem to make sense either due to the the single letters being repeated.