I'm looking for a Ford/Thompson power steering pump pulley. I need one that uses the 2nd groove on the water pump/crank pulleys. My current p.s. pulley uses the 3rd groove on my w.p./crank pulleys. I don't know the Ford part number for the one I need. I'm pretty sure these where used for Mustangs with A/C and in trucks with a single groove alternator pulley. Some of these, maybe the later version, are marked "7AA". I think it was first used in 1967. This is for my 1970 truck if it makes a difference.