From what I could tell, the main problem is that you need the late style timing cover. This is a royal PITA to replace by itself (it would be much easier with either the oil pan or heads removed). I haven't yet determined if the AC bracket must also be swapped, or if the 6/8 rib belts & pulleys are interchangeable. I plan to try and convert the '92 engine to a 6-rib pulley setup with manual tensioner for now, and later on swap the cover and convert to automatic tensioner.