DD,
Ok, I got your pictures and did a little research on the engine casting number. The 3835913 is actually the HEAD casting number and is correct for the late 53 thru 55 235 engines.
You should find the engine casting number 3835911 down low on the passenger side of the engine block, near the oil fill blow by tube.
I still can't explain the manifold casting numbers...or the SWK in your title and door post numbers. I wonder if this was added at a later date my the MVA or State when the original motor was pulled? Do the numbers all look like the same machine stamped them?
Mike B
