Engine assembly date stamping

[Edward McComas]

When did Chevrolet switch from 3 digit date codes for engine assembly dates to four digit date codes for engine assembly dates. As an example:

F424EL for April 24th, 1957 FI engine

F0424RF for April 24th, 1963 FI engine

I was under the impression (probably incorrectly) that Chevrolet only used four digits in the assembly date when 3 digits could possibly be misunderstood. Something like F112 could be taken as January 12th or November 2nd. So it would either be F0112 of F1102.

Whats the story here?

[John H.]

Re: Engine assembly date stamping

Ed -

The survey data on page 305 in Noland's book indicates that the 3-digit date code changed to 4-digit effective with the start of the 1960 model year; that's the only printed reference I've seen on the issue.