I have a 2002 f150 xlt with the 4.6L, with a 6" suspension lift and 35s looking to upgrade my gears from the stock 3.55s to 4.56, I have the 8.8 and am wondering if the 4.56s will fit in the stock carrier or not and does the front have to be reverse cut or just normal cut? Also what benefits and disadvantages are there when going to the 4.56 when running 35s or 37s?

 

You don't need a new carrier but you will need a notched crosspin. Front must be reverse cut. Get the gears and master install kits. 4.56 is the right ratio for that engine and tire size. Get a programmer with custom tunes.

 

I have a tuner already from SCT So il just need gears, forward and reverse cut, install kits, and a notched cross pin and il be fine then?

 

The shop you get to change the gears should know what it needs.

 

well the thing is it's most likely a friend and I doing it since he has done a few before no issues and I can buy all the parts basically from summit and do it, just trying to figure out everything I need and Info before hand!

 

Setting pinion depth, getting the exact crush on the crush sleeve, and setting backlash is critical. Good Luck!

 

Thanks so basically everything stock wise should work and beable to be kept instead of changing everything out like new diff housing and whatnot

 

You may want to replace the LS clutches while you are in there (if it has LS), or consider getting an Eaton locker.

 

Thanks I probably will while I'm in there!. Thanks for all the help. Some places was saying that 4.56 won't fit at all and I'll have to upgrade everything completely and others said it will. That's why I came here and asked to get a direct answer. Trucks only got 70k on it so I'm trying to do everything right to keep it going