I just picked up an engine from a nieghbor and i have no idea what it is. The numbers on it are 3970010. Thanks

The 010 on the end means its a 4 bolt.

The 3970010 was a popular block with 4 inch bore used from 1969-79. It was made in both 2 bolt and 4 bolt versions. You would need to pull the oil pan to find out which one you have. For the 1969 model year, this block was used in 350, 302, and possibly 327 engines.
For further identification, you need to check the the stamped numbers on the pad on the front passenger side. These numbers will tell you more about the application it was used in.