Crankshaft oil slinger for all small block Ford V-8's, starting 1963 until at least through 1973. 1963-68 289 and 289 HiPo engines. 1968-73 302 engines, 1969-70 Boss 302 engines, 1969-73 351W engines. Goes on the crankshaft after the timing gear and before the timing chain cover. It does have a purpose on the vintage engines.
Ford part number C3OZ-6310-A.