That thread sounds really sketchy to me.
I'm not sure what the fitting is for but the guy that made the kit appeared to chime in a time or two and said something about using an F150 inline pump and some sort of S-AFC to manipulate the MAF. I don’t like the sounds of that. 1) The MAF should be upgraded and a new tune made; not manipulation tactics which is a band aid and will more than likely give you more troubles. 2) If these OHV explorers have mechanical return less fuel systems, like the one I have with the SOHC, the proper thing to do is drop the tank and upgrade the fuel pump. Using an inline pump, like the kit maker suggested, after the stock pump has regulated in the tank itself is not a good way to keep fuel pressure regulated. There was a post made by Doug904 where he told the right way.
This thread is old and I believe there are much better ways to do this. There is a guy named Turbo Cat that you may PM and ask about the OHV engine but I wouldn't do anything mentioned in that thread. IMHO