Would anybody be able to shed some light on the E288 on my 68’s trim tag? Thanks

Unfortunately, those codes have not been decoded.

Geoff,

It seems like they seldom appear on '68 Firebirds and there is no known Firebird decoding.

I did see a '68 Camaro body/trim tag decoding that may/may not explain the codes, although the code doesn't seem very significant.

With both Camaros and Firebirds built at LOS, I wonder if some Birds got the code from the Fisher side of that plant??

See: https://news.classicindustries.com/camaro-trim-tag-decoder

F. Fisher Body LOS Scheduling Code
The Los Angeles (“LOS”) body scheduling code consists of a letter followed by one to three digits. The letter indicates the production day of the month for the beginning of that vehicle’s assembly. The letter “A” indicates the first production day of the month, and was reset the first production day of the next month. The three digits represent the vehicle’s approximate production number each day. At the start of the next day, the code was reset to “1”. This number is exempt from body style, thus a Full Size vehicle could be serially located just before a Camaro or Nova. This code was not used on Norwood built vehicles.