The Atlas is more durable than a 300. Not too long ago on a trail who's name cannot be mentioned a certain Dana 300 equipped CJ ended up in front high and rear low (again). Not a pretty sight. By the time you buy a dana 300 (In questionable condition because it's 20-30 years old), pssibly rebuild it, flip it, clock it, upgrade both output shafts (the front is still not readily available), regear it, and twin stick it, you could have bought a brand new Atlas built exactly how you want it. Oh, and your 300 is still not as strong! The Atlas is the king of transfer cases.