Just read thru this whole thread and one thing I didn't see was checking the driveshaft slip joint at the transmission (except for your last post). On Ford Superduty trucks, especially those with 2-piece rear driveshafts, it was common to get a pop on takeoff if the slip joint dried out. The cure was to lube the splines on the slip joint. Ford recommends a teflon based grease for that purpose. You may be experiencing the same thing.
If the splines are worn (you did mention some wobble at the front of the driveshaft), that could be the cause of your noise.
