[L78M22Rag]

I got this off a Corvette forum...

“The ECL is an Exceptions Code List. It was used at the factory to let the line workers know what items were to be installed.

Each option or trim combination number was assigned one or more ECL (Exception Control Letter) codes based on what OTHER options were combined with it on a particular car, as OTHER options would change the parts required for the option being listed, and the parts list generated for that car needed to contain all the correct parts for the specific options ordered. For example, the parts for C60 Air Conditioning for a big-block car were different than they were for a small-block car, so each C60 application carried a separate ECL code in order to generate the correct parts list. Similarly, a blue interior for a Powerglide car required different interior parts (the console) than for a 4-speed, power windows required yet another different console with or without Powerglide, power windows required different door trim panels than manual windows, etc. ECL codes kept all this organized so the computer could order the correct parts for each car before it was ever built.

Consoles are a good example of how "combinations" affected a single part and "exploded" it into many finished part numbers - there were six basic interior colors for the console, which was received already painted, for six (base) manual transmission part numbers. Powerglide doubled that, to twelve part numbers. Power windows doubled it again for both of those parts, to 24 different part numbers to order and stock on the line (six colors of manuals without power windows, six colors of manual WITH power windows, six colors of Powerglide with manual windows, and six colors of Powerglide with power windows). Without ECL codes assigned by Engineering to each possible combination of option and trim colors/materials when the parts were originally released, it would have been a nightmare manually figuring out which parts to order for each car. That's why the window sticker shows a 2-letter ECL code after each option number - so the car's order specs could drive the procurement system computer to order exactly the right combination of parts for that particular car before it was built.”

Ya learn something new every day.