VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1939 car engine casting numbers ??

Folks, since I am new here, please excuse questions that may already be answered ! I am asking what the engine casting numbers on the side of the engine block may mean ?
I have a 4-door '39 Master Deluxe and upon overhauling the engine, we have found the casting following letters, and numbers.
First is the big GM lettering, underneath that is 838941, then a 3'rd row, or line, with 17. All stamped into this engine block.
Does each number actually mean something ? If so, what ?
Then the 17 ....mean anything ? Sure would like to know since this car has been in our family since the 1960's and I am trying to keep it original pretty much.
Very much appreciated, thanks for any and all answers !!
Also, is there a way to be sure the vacuum shift is actually working like it should, is there any replacement items for this, if something might be missing, thanks again,



MJD

838941 is the casting number for a 1939 block only. The 17 means nothing but there should be another set of numbers that would indicate the date the block was cast.....around the conv letters.

If the vacuum shift is working the lever will move very easily when the engine is running and very difficult to move when not running. 1939 vac. shift parts other than the actual cylinder can be difficult to find as it was a one year only design. Everything was slightly different for 1940.

Chev. Gene, thanks for fast reply, I know this car has a motor number or an engine number on the block too. It does correspond to what the title says too, I think lots of cars ID, or VIN, was the actual engine number back then.
Our '39 4-door is stored in town until we get the engine complete, so I do not have that engine number to see right now. Was this your question about another set of numbers ? I know there is a tag too under the hood telling the trim, body number, etc. I just would have to look it up again to write these things down, I just haven't messed with looking at the car until we get the motor together again.
Thanks again for your help and time ....

MJD

Most states used the engine number for registration prior to 1955.
The serial number will indicate the month assembled. The we will see if the engine number sequence falls into that approximate time frame.