Since it won't let me cut and paste I will tell you how to view it. Go to '57 Model Info on the directory bar. Then scroll to the bottom of the page. It lists the 277, the 301, and the 318.
I know it is not the 4 bbl. 301 but, that is all I know for sure.
I cannot find a P code anywhere on the front or sides of the block. I cannot see the back of the block in the driveway.