Reservoir Attaching Nut 351335-S38 - Used Nuts for attaching the oil reservoir to the pump. The larger of the two nuts goes against the can. Threads of 5/8"-18 to fit the high pressure port. This is a pair of nuts, one tall and one short.
Please follow the assembly procedures for the Ford power steering pump in the Ford shop manuals. Fits all small block V-8 engines, except for 1970 with 351 engine, and Mustang with 302 engines. 1970 302 / 351 engines used a different pump with an offset pressure fitting and a larger nut.