my most recent project-71 lark- had a swap from 6cyl to 350 sbb at some point in its life prior to landing at my place. when i drained the oil it was extremely dirty and i decided to pull the pans and take a look. yuck! anyway when i turned the engine upside down to check the bottom end i found these numbers stamped in the block surface under the 1st and 2nd piston where the oil pan gasket lies which read "030". any one know what this means? ou:
