Some front diff had a disconnect collor on 4x4's, the AWD will not have it, not exatcly sure on when that style front diff. was ended, I know the 97's do not, you dont want the disconnect style diff with AWD. Now, an LSD in the front is possible, but not recommend on the street, Best bet for the front diff would be an air locker that can turn "on/off" for off road use, this makes the vehicle alot more comfortable on the hard pavement.