Glove box was a different key on early ad trucks just like the cars where in 1950 the door and ignition are different than glove box on purpose
Then later by 53 for sure to reduce cost all keys match
I’m not sure when the change was made
That is why there is a octagonal head and a round head key
The oct. head shape is the ignition and door and the round head key is the glove box
-s
This was what I had always thought to be true. When I bought my 47 GMC it did not have any keys. I pulled the door lock and had the key cut from that code. To my surprise it worked the ignition and glove box as well. I was not lucky enough to have the spare tire lock. I have since found an original owners manual for the 47 GMC and it states that one key operates all locks. Not sure if Chevy was different from GMC in that respect or if, and when, any changes to that policy were implemented. I do recall from my experience that if the glove box lock will not open with your new key, it is best to just buy a new reproduction lock w/key. The proper code for the glovebox lock can only be revealed by removing the cylinder from the lock assembly which requires a key. Or in the case of no key, trying to find a talented locksmith to pick the lock, remove the cylinder through a process most locksmiths have long forgotten, get a key cut and then put it all back together. Easier and cheaper to replace. If it is currently unlocked you might consider just leaving it unlocked anyway. If somebody wants in and does not know enough to use a sharp knife underneath and cut open the cardboard, they will destroy your dash prying it open. My lock works but I will be leaving the glovebox unlocked.
