"G74" on pistons

[Dion]

The cilinder head is off my 75 2500, and has new hardened valve seats inserted.<br>When scraping / cleaning the pistons I noticed they had marks in them.<br>All have arrows pointing to the front of the engine, a capital A in the middle, and little smaller G74. Does anyone knows what that means?<br><br>I don\'t think the engine has ever been opened. There was a Stanpart head gasket still fitted.<br><br>just curious,<br><br>Dion.<br>