Went to Junk Yard for First Time in Months....Here's What I Found

Ok, went and looked at the 77 Truck with the Chrome valve covers and square bore intake.

Discovered, actually, that it's a 400. For some reason on this one I failed to check for the pad on the front. When I was scraping the oil off the side of the block for the year and numbers, I found that it is a 400....obviously, cast crank. Someone must have put an old 383 intake on it as well as the valve covers. The valve covers had the wire tabs on em so they appear to be factory....not sure though. Any thoughts?