I think the carriers are fine.
@Jody Treadway should be able to verify.
ARBs are cool, but it's either open or spool. Plus, they're like 1200+ doll hairs...as with almost every traction device for an AAM 11.5 or 11.8. I wish they'd get an E-Locker for them though, that'd be sweet. Limited slip when off, locked when on.
That said, I want to throw 4.10s in my 02 as well. My mileage never changes from 65 to 90 mph and it would put me at 1900-ish RPM at 65 mph and the non VGT turbo would be much happier when towing.