[Jbo68cst]

So I came across an empty block on a stand at one of my neighbors house. Got the casting numbers but can't narrow it down to one thing. Can anyone help?
3969854 B 20 70 GM 8
It's a 4 bolt.

 

[buenymayor]

3969854 is a 402 block. We'll need the pad stamping to tell what it originally was out of. B 20 70 is the casting date..... Feb 20th, 1970

 

[David Bates]

And, as it is a 4-bolt block it should be an L78 which could have been originally installed in a Chevelle, Camaro or Nova.