Today I spent some time going over the Authenticity Manual for Class 16 cars, and making some checks and comparisons with my vehicle, #966.
One thing I discovered is that the rocker assembly covers (or valve covers, if you prefer) have the BLOCK letters rather than 'Cadillac' embossed in script type. (Authenticity Manual - Class 16, 1957-1958 Cadillac; pp 111-4 to 111-5, section H). However, the machine screws are Phillips, not hex, and do not have any markings.
These covers seem to be original (flaked off paint, dings, and other indications that they do indeed date from 1956 when the car came off the line). Also, this is a family car, and I have a pretty good grip on its history.
Interesting, but probably not remarkable.
Anyway, just an anecdote for future editions of THE MANUAL (which, by the way, has been extremely valuable to me. Personally, I would consider it required reading for anyone messing about with old Cadillacs).
A better photo of the rocker cover...
Attached is a picture from the '57 Brougham engine I own. The letters are the same as on your valve covers. Of course, the paint is different as the car has the 2 carb set-up. Therefore, your valve covers are right.
Thanks, Roger. As I get deeper into this project I'm finding that there are many exceptions to the 'rules' when it comes to what is considered standard.
Script on the valve covers? My 1959 has block letters. I know it is all original.
My 1966 has script. Did the script start in 1965 maybe?
Perhaps the script changed to cursive when the engine was redesigned for the 1963 model year. My 64 has cursive script on its 429 valve covers. It's likely that the 63 390 did too.
Also, I have seen Chevrolet V8s in the mid 50s using Phillips type screws for their valve covers, so yours may well be correct and original. That would be my bet.
That is correct- "Cadillac" script replaced block lettering on rocker covers in 1963 with the redesigned 390 that year.