Late summer 1963 casting. I don’t have my parts references handy but if it is for a small V8 it is for 260/289 Ford engines that were fitted with manual transmissions. Timing wise that is early in the 1964 model year.
SHEFFIELD is the town in Alabama where Henry Ford had a large hunting camp and where he put his aluminum die casting plant when the Tennessee Valley Authority put a dam and hydroelectric generation plant nearby and provided low cost power. The plant was sold in the maybe the late 1970s or early 980s.
Here's one link to Sheffield's past, you can find many more.
http://www.al.com/living/index.ssf/2013/01/post_89.html
Ford's aluminum casting plant made most Ford made aluminum die castings there for decades. I lived nearby and had friends that worked for Ford. My father was a metallurgical engineer and researcher working in Huntsville employed in the manned space program. The local professional engineering society chapters serving a variety of industrial and aerospace communities use to visit the Ford plant regularly.
Ford got out of the aluminum casting business in Sheffield but not before “recycling” untold numbers of Ford performance parts from the 1962-72 time frame. When Ford bailed out of “racing” circa 1971 it recalled inventories of aluminum performance parts. Yes, they also recycled obsolete castings of all kinds after most the cars they came on became ten or more years old but the performance part recycling was on an enormous scale. Dealers could turn in parts listed as obsolete for credit and Ford would destroy them. Thousands of aluminum rocker arm covers, intake manifolds, and cylinder heads from them the Total Performance® and Muscle Parts® programs were shipped to the Sheffield plant: Ford DOHC INDY type cylinder heads, Boss 429 cylinder heads, dress up aluminum rocker arm covers, and aluminum 4V intakes by the truck load. Circa 1976 I met a fellow selling C9OX 4V intakes for 289/302 engines with 351W 4V cylinder heads out of the trunk of his car for $16 each as many as you wanted. When I asked where they came from he said the Ford scrap bins. I didn’t believe him and then he told me Ford was paying mostly high school and college age people to unbox returned parts and toss them in the big bins that fork trucks would move to the furnance area for melt down. He indicated that most of the parts were of little interest, like what could you do with a DOHC INDY cylinder head or Boss 429 head? On the other hand, the C9OX FORD lettered intakes would bolt onto any 260/289/non-Boss 302 engine and there was enormous market for cheap intakes. Anyway, he said one of the unboxing crew tossed these intakes over the fence and went back after work to get them. He was selling them super cheap and the guy I met selling them for $16 each was making a very large percentage profit. I didn’t want a stolen intake manifold and ended up buying an Edelbrock intake at Pat Gray’s speed shop.
So where did the Cobra, INDY, and Boss aluminum go after remelting? Into Ford Pinto transmission cases one of the plant’s QC Inspectors told me.
Hybrid Mode
