tuner for the speedo, ours is off 15 pmh since we have put the 4.10's in our rearend

 

if you've never done it, i would high reccommend getting a professoinal to do it, especailly if your dont even know what a dail indacator is, you def wont know how to use it, if you do it yourself, backlash it is the most critical part of the instal so i would get a chilltons book or something, or you'll for sure be in the complete dark! are you going to leave the axle in your car, do you have a lift? if not, i would pull the whole thing, it might take longer but you'll have a better time doing it all, instead of onyour back

 

**highly