The only pictures that are really meaningful are of the side of the block, the first three.
The front of the block, where it's got cast 352 doesn't mean anything. Virtually EVERY FE block has that number on it. The head number, C8AE-H, would date the heads, but OFTEN different heads are found on 427 blocks.
BUT, as bdriver noted, lets ASSUME these are the original heads that came with the block. In that case, sure enough, likely a 1968 427 drilled for hydraulic lifters.
Moveing on. It does have the requesite screw in freeze plugs (a MUST HAVE to be a 427 side oiler). It also has the side bolted 4 bolts mains (3 per side), again a MUST HAVE to be a 427 side oiler.
It DOES have the
oil galley on the side AND the screw in allen head plugs would lead one to believe the block is ACTUALLY drilled to be a side oiler. SOME blocks were cast as such, but not DRILLED as such, leading to massive confusion such as we have here!
Most likely these ARE 427 side oilers!