IMHO, the thin side of the housing tapped by Jadaharabi looks to have the major thread diameter almost through the housing. Not to mention the fact that pipe thread has to be tightened to hold and seal, and that exerts a lot of outward force on the female threads. I'd be welding/brazing some reinforcement around that area, as well as paying attention to strongly supporting that very heavy piping used for a pickup. A decent sized pothole will put a big shock on those threads with all of that weight hanging out there.
