Buick59

I have a 1968 Corvette convertible with a 427 and a 4 speed. When I looked through the paperwork that I got with the car I found the original protecto plate in the file.

Can the protecto plate tell me what 4 Speed came on the car? I am unsure if it is a M20 or M21. I have not been under the car to look at the tranny.

I can do a pencil copy of the Protecto plate if that helps.

Thanks

Todd

ed427vette

In 1968 I don't think the protecto plate will show you which transmission. The info you will see on the plate will be something like P8B10 which would mean P - Muncie, 8-1968, B-February, 10-10th day. That would be a copy of what is actually stamped into your trans, assuming its original. In 1969 for instance they changed the trans stamp during the run to reflect which trans you had. Early 69s used the 68 system. not sure when it changed, but at least by January they had the new system, maybe earlier not sure. However, the 69 pop did NOT change and did not have the extra info on it. A revised 1969 trans stamp would be P9B10B. Its translates the same as the previous example except the 9 would be 1969 and the second B would be M21. If the last digit was an A it would be an M20. If a last letter C then an M22. If it was an automatic its a totally different system of characters.

Also the letters for the months were not in order. They skipped for some reason. For example a B might be February but off the top of my head I think December was T.