I have an 02' 2wd with the H9 rear end so it should be a 3.55LS right? Also I am trying to confirm that it is the Ford 8.8 regular rotation. I am looking at getting a set of used 4.10s, they are out of a mustang 8.8 and I just wann amake sure I am getting the right gears! Thanks

 

also I think I need an install kit...and obvoiously fluid, but is there anything else? Where's the best place to get an install kit?

 

H9 is a 3.55LS. As far as the size, it depends upon the engine. If 4.6 it would be 8.8, if 5.4 it would be 9.75. You can verify this by looking at the tag on the diff. It will have something like 8 8 or 9 75 on the tag.

 

ok cool...also the tag says 3L55. I work with a guy that did ford parts for years and he says that I have a ford "locker" and that if it was a limited slip it would say 3LS55. The point is that when I go to spin the tires it spins one like an open diff, and I want to figure out what is wrong so I can fix it when I have it apart.

 

Ford does not put lockers on there trucks, at least before 2009. It is a limited slip. It is possible the clutches are bad on the rear.

 

ok cool, thats what I was thinking, but he is a pretty knowlegeable guy. Any idea where to get the clutches and what they cost? I have heard there is a possibility that new fluid with friction modifier will fix the problem, but Id hate to pull it apart change the gearing and then still have the problem!

 

double check before you buy bud. and the master install kit is what your going to need. i have the 5.4 and put 4.10's in it. mines an 02 f150 5.4 2wd. made a HUGE difference city driving.

 

mustangs are 28 spline 8.8s and yours would be a 31 spline 8.8

 

are the ring & pinions the same? I found out that I can get a good deal on the gears through a friend of a friend so I may just get the right ones new. So all I need is the gears and the install kit then? what size tires are you running with the 4.10s? My 4.6 runs pretty decent with troyer tuning, intake, and exhaust BUT it can still use every little bit low end power it can get! I am running 265's right now and its decent but stepping up to 34" terra grapplers and I know its going to be a dog! I hope the gears make a big difference to compensate for the tires