dana makes detroit lockers for 8.8" and 9" Ford, as well as a bunch of other Ford rear sizes like 10.5s etc., but that ad says it's from a dana 44... dana 44 lockers are for jeep axles... i'd also reconsider putting a locker like that in a daily driver, they're temperamental and hard to get used to from everything i've heard
just look for a complete rear end from a junkyard or buy a trac lock rebuild kit from LRS and have a professional rebuild it