Can't help you on the adapter joint you are after however I can offer some use experience. I prefer maintenance free u joints for a few reasons. First greasing them is a PITA to remember when and you are guessing if you are between service intervals if there is enough in them or not. A service type U joint has loose seals so the grease can sling out over time, this is by design but those loose seals work backwards as well by letting dirt and moisture in. Another issue is the unsightly and mess they make on the tub when the grease slings out, if you grease it fresh, just how many rotations do you think it takes for centrifugal force removes half or more of what you just put in, my guess is in just a few miles the positive pressure that would keep things out is no longer there so there is a void that will suck in debris and moisture when they cool. Non service U joints don't have the drilled hole and cavity for adding grease so the trunnion should be slightly stronger, they have stiffer seals to retain the grease and the underside of your bronco remains clean. Now if you want you can still service them by pulling them down and pulling the caps to add grease. We always check the grease that is in them prior to install and add some if I see one has slightly less than what's under another cap, don't over fill as they will leak till they get to the right volume when heated from use. Hope this helps. One other tip, if you are in need of a high angle driveshaft, a non service double cordon joint will flex a lot more than a serviceable one achieving a higher angle and without the mess and maintenance. My driveline guy does recommend if you are doing a lot of off roading to still have them serviced once a year for like a rock crawler or mud truck due to the constant harsh environment but for a rig that sees occasional off road and mostly on road he said run them till they make noise and replace them. He has seen an average lifespan of normal use to be about 100,000 miles, tow rigs get about 80,000.