If anyone has questions on which diff they have feel free to shoot me a pm i'll give you some instructions on how to find out what diff your truck has. toasty has found that not all Gen 2 auto 3.0 V6 have the small 4 cyl diff and axles so if you own one of these and want a locker up front there maybe some hope without having to swap a diff.

89 2 dr turbo diesel
89/88 "Backwoods sas"