Help with Engine ID

I have been looking and searching, but I haven't been able to find the info I need. I was told the engine was from a 1950 Pontiac. The only numbers I can find are GM 3 514386 top of head, half way down from the thermostat. I took off the paint from the L side "lip" and saw 1 and 7 (7 further apart than the 1 is). Right in front of the thermostat is J17. There are 4 freeze plugs per side. Bottom left of the oil filler, shows 3320. Distributor number is 1110222 9M21 Delco Remy. I have found info on the location of engine ID on all Pontiac motors, other than mine, seems like. I do need to order a tune up kit, I thought it would help to know what year car the engine came out of.

Can anyone tell me where to look, and does anyone know from the info that I provided what year is my motor?

Thank you guys ​

I had to ID one awhile back- I located the stamp on the front, left hand side of the engine. I believe it should be directly on the front of the block itself.

Thanks. You are probably right, but there is not enough room for me to see. I used a mirror, I tried from underneath, both sides, the radiator needs to come off, the front trim, and I am just not in a mood for all that. I keep searching , hopefully something will come up. Appreciate your help though.