Help Engine Identification!No VIN on Engine Stamp

[vanleer4]

I know this question has been ask a million times a tons of info on the web, but mines actually an unusual case.

I have attached photos of front plate/casting numbers but still no ID ( the front plate has no info I took all paint off). even the clock where it shows when it was made (but no date stamped by the flange by clock).

I cant find vin anywhere on engine even by the oil filter where some were hidden.

Does anyone know where else a vin maybe stamped on engine block or location. This engine is either a 327 or 350 due to the stamp of #3970010 but that's all the information I can find on her that helps identifying her. I'm trying to figure out if she belongs on my C20 or not

Any information is much appreciated.
Thanks
vanleer4