What engine did I just find?

Yesterday I bought a 318 "Smog" motor as it was advertised. I bought it for the peripheral parts only, brackets, valve covers, and such. The engine was complete with transmission.
This morning as I was disassembling it I started checking casting numbers
It caught my eye because of the four barrel carb. The manifold numbers show that it is a 318 four barrel.
It is a February 1981 318. When I looked up the casting number it came back as a "Race Engine". What is this? A cop car engine? Any help would be appreciated.

[URL="http://i218.photobucket.com/albums/cc58/Crytot/Casting.jpg"][/URL]
[URL="http://i218.photobucket.com/albums/cc58/Crytot/Manifold.jpg"][/URL]
[URL="http://i218.photobucket.com/albums/cc58/Crytot/Carb.jpg"][/URL]
[URL="http://i218.photobucket.com/albums/cc58/Crytot/CompleteUnit.jpg"]
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