Restoring this 1954 Ford F250. Not sure if the 6 is original or not. I don't think so but I'm not 100% sure. The intake manifold is cast C3. Here are some pictures attached.

 

1954/64 came with the 223 I-6 as standard equipment.

1954/59: Valve cover retained to cylinder head with two studs/acorn nuts. 1960/64: Valve cover retained to cylinder head with 8 bolts.

C3 manifold: Original 223 exhaust manifold part number was replaced in 1963 by C3AZ-9426-A

The 223 manifold is notorious for cracking, NOS no longer exists, used very hard to find without cracks.

 

That sheds some light. Does the casting number on the block mean anything? Also, what is up with the oil line running to the top of the valve cover. It taps into by the sending unit for the oil pressure gauge. Is this how the rocker shaft was lubricated?

 

Figured out the goofy oil line. Unfortunately I discovered a minor catastrophe.

 

Looks like a stock 223 to me. Is that a broken rocker shaft?