That would be the one. Ford has two 4.0 V6's. The older OHV like we're talking about and the OHC which is a POS. That's he one in all the Explorers with ''blown'' engines that rattle.
It's a really screwey design. Most OHC engines have a seperate head for left and right due to the cam drive on the front of the engine. On that Ford, the heads match so one head has to be driven from the rear. So they put a jack shaft where the cam used to go. That way one bank gets driven from the back of the engine. The front of the engine has two changes, one for a head, and one to drive the jack shaft.
I used the special tools one time to replace the chains and time the cams. It was a MAJOR PIA, and the engine was on a stand. There's no way I'd ever attempt it with an engine in the vehicle.
I actually thought about buying every Explorer I could find with loud chains to flip, but that repair is just too messed up! lol