Hope someone can help me. Looking at purchasing an engine but need help with the codes stamped on it

heads casting # 3931063 gm4t k27, 3931063 gm4t k29

Block casting # 3963512

and the hard one for me? block vin 13k034420

I was told number match a 69 but what and what car and hp. Can someone please help, I am a novice in training. Thanks

Just about same motor I have in mine, out of a 69 Impala. http://impalass427.com/69engine.htm

Thanks for the info. How do I tell what hp came with this engine. There are so many different ratings for this setup.

With that block they are telling me 385 HP. But are also asking me to check the plugs by oil sending unit as it may be a 4 bolt.http://members5.boardhost.com/impalass427/index.html?1126411983