Casting numbers behind timing cover.

[doc396]

Is there a chart to ID these casting numbers behind timing cover?

 

[Don Jacks]

Not really Doc.All those tell you is that you have a 4 inch bore block.

 

[oldskydog]

The 010/020 are merely the last 3 digits of the casting number (3970010/3970020) of the block using that same end form (pattern). 010 being the flint 350 and 014 being the flint 307. The Tonawanda version would have 014/024 (3970014/3970024) being 014 for the 350 and 024 for the 307 .If there are several casting numbers being used at the time that block was cast, as in 870 (327), 721 (327 Chevy II), then those numbers would also be on there if that same end form was used on all the small blocks being cast at that time.
The same is true for for the rear end form.

BTW, they have nothing to do with the nickel content or any other metallurgy content.

 

[Phil Reed]

Here I thought it meant that the crank was 10 under on the mains and 20 under on the rods??????!!!!!!!

 

[doc396]

Oldskydog, that is what I had heard, about the metal content. I knew someone on this site would know. Thanks