Block Stamped c c a b on the head surface

[Command52]

Any idea why this 1950 cub block is stamped {Starting at the front of engine.} c c a b I'm prety sure its been rebuilt before , The pistons are stamped 030. Why would they stamped it using 2 C,s. How much more could it be bored out if needed if it is already 30 over if this is what that 030 means , Also look between the cylinder and the valves on the one cylinder . I see some pitting How much can the block be machined to fix pitting.

[Jim Becker]

C C A B indicate relative sizes at the factory for selective fitting of pistons. Since your block has been rebored .030 over (as pistons indicate), those letters are now meaningless. I believe the block can stand boring to .060, but your practical limit now is determined by whatever pistons you can find.

Here is a recent discussion related to pitting of the block:
viewtopic.php?f=1&t=99822&p=787680

[Command52]

I cleaned head gasket up and it is stamped with the same letters on the back side of the gasket

[tst]

that is just the impression that was made in the gasket from the block by tightening down the head bolts