Stop randomly throwing parts at the car.

You need to confirm that the internal trans gear ratios are proper. There are at least two ratio sets for USA cars and a bunch others from when Chrysler was part of DB.

Also, If you have a 2 speed transfer case I'm thinking there needs to be some way that the TCU knows the transfer case is in a different speed. From another thread in a rear drive car, someone swapped rear ratios and hit limp after the trans shifted into 4 th. It drove just fine when kept in 3rd. Apparently the TCU checks that trans input and output shaft speeds match what is expected from wheel speed.