4x4 5.2 would be 44RE. I've seen a few original motor Jeeps with over 370k.
Dodge never offered 4x4 vans- Ford did because they got wise that Pathfinder & similar companies were buying Ford spec Danas to put under every kind of van. Vans are a pretty good donor since many vans even had 3spd hydraulic transmissions which means you can use basically whatever transmission you choose. The van 32RHs (904/998), 42s and 44s all have low 1/2 gearsets and I think the better front pump setup than earlier 904s despite being lockup.