69 zl1?

[William]

Originally Posted by The Boss

Can anyone tell me the significance of the numbers on the caps?

Many years ago I corresponded with Fran Preve, who worked at the Tonawanda engine plant. He said at that time, Tonawanda did not have tooling that could simultaneously cut steel and aluminum. After fitting the main caps to the block, they were removed for align bore or hone, maybe both. They had to be numbered so they were re-installed on the original block. It appears they were number in sequence; must have maintained a log.

Fran is no longer with us; was a great guy. He was the source for all of the big block production figures back to the '50s.