Thanks I did call a dealership who said that it was an option for 2001 and I was concerned about the 11.5 not turning as fast as the front when in 4wd he said the 11.5 was built heavier and teeth were spaced so they would turn the same as front when 4wd was engaged. as long as it was 4/10 gears he thought i was ok,,,,, I am just looking for another opinion before making this switch,,, sure hate to install 11.5 and have an issue with it and have to tear it apart again. Thanks