The crankshaft oil slinger is part number D0AZ-6310-A.
There are 3 sources I normally check for obsolete 351C parts:
1. Ford: Although 351C parts are obsolete, the 351C shares many parts in common with the 400, which was used in Ford pick ups in the late 70s and early 80s, and in the large Ford sedans too. Many parts are still listed for the 400. I normally reference a 1978 F250 with a 400 when I go to the Ford parts counter.
2. Perogie Enterprises of Hightstown, New Jersey: The business is owned by the Porubski's. Their pricing is expensive, but they have always had the part I'm looking for. I've been doing business with them since the early '80s, never had a problem.
3. DSC Motorsports of Anza, California: Dennis Carrico does a lot of 351C parts business on eBay, he has a lot of the little parts that are needed to assemble a motor. I've purchased a few things from him, never had a problem.
I'm sure there are other such sources, these are the ones known to me. I have an oil slinger on the shelf at this moment, I purchased it from Perogie Enterprises.
cowboy from hell