Is 2001 the first of the IRS rears? On the Gen IIs, one axle shafts is different (shorter) for the locked rears. Don't know if there are differences with teh Gen IIIs. I would be worth checking on before you pull the open rear.

As for the air actuated, do yourself a favor and get the pump and switch from the XLS.

Big Truck: 00, 3.5, Endeavor, 5-Spd drive line in hand!
Little Truck: 87, 2.6T I/C, MT, LSDs, Tonneau Top
Her Truck: 03, 3.8, 20th Anniv, 65k
Daughter's: 06 Eclipse, Keeping it Mitsu!
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