Help with pontiac engine numbers

Hi everyone, i need help with this old pontiac. i found these numbers on the engine and need to know what they mean. the first one is GM 517293 ,it is cast in just above the oil pan right under the dipstick on the drivers side.the second one is J 30 3 , cast closer to the trans but beside the first number , the third one is hard to read and is upside down but it looks like it says 3040
4657,and it looks like it was added by a human instead of a casting. Also is the cars vin number cast on the engine anywere? the car is a 1953 pontiac chieftain and its a canadian model.
thanks .

 

Hey pete ,, dont know much about Poncho #s. But mortec .com site always helps for Chevs. It may help you. btw,is helps to tell about yourself first. Got my 52 in Ed. nice town...WELCOME 52 csb

 

The J 30 3 number looks like a casting date, October 30 1953 is how it would be decoded.

Nut much info on the internet about Canadian numbers unfortunately. Also not much interest in the old straight 6 or 8 ponchos.

 

built in oct? maybe she's a 1954 . is there a vin # on the engine somewhere ? the one on the door frame is missing . thanks for the info so far any help is really appreiciated.

 

If there is a motor number (there probably is) it should be stamped, not cast. Usually there's a flat machined surface somewhere that the number would be stamped on. US pontiacs 48-53 had the number stamped on the top left hand front corner of the cylinder block.

 

i found it under some greasy slime , the stamped number is W265669 .
what does it mean?

 

W is probably a build plant, the rest a sequential production number. It may or may not have matched the serial number on the car.

 

On US models W is a 1952 (X would be 1953).