Is this a 3963512 casting?

[DavidS]

I recently bought an engine that is supposed to have a 3963512 casting #.

I can make out 39?3512 with a sideways P below.

The 512 is very clear. Are there any other GM big block engines ending in 512????

I searched like crazy on the web, but could not find any. The third digit in is a mess. I gently scraped some of the paint off, but I still have no idea what number it is.

Here is a picture:


This is a pic of the area above the casting number:


Is the date code is supposed to be here?


Any help would be greatly appreciated!!!!!

David