I think I found the casting code between the distributor and the tube on the right.It is hard to see, but I think the number is 3769716. Inliners.com says that is a 1960-61 235 engine. Still can't find a serial number or date code, but I will keep looking.

1954 Chevy custom 261CID, T-5 5 Speed.
1952 Chevy 6400 2 ton hydraulic flat bed.