i have a 2006 fx4 6'' lift 35's 17' want 37 but have stock gears and i want a little bit more quickness out of it i have a hypertech and an airaid intake but i dont really know anything about gears so somebody help me out and explain them a little, tell me what r the best 4.56 or 4.88 ,where to find them ,and how much

 

If you are going with anything bigger then 35's then go with the 4.88's.

The two links below have a ton of info in them. The first one covers a lot of the basics, and the second one is a link on how to do it yourself.
1. https://www.f150online.com/forums/ot...supercrew.html

2. https://www.f150online.com/forums/ot...p-rev-1-a.html

 

ok thanks so do i have to change the front and the back or just the back and what is the 8.8 and 9.75 and what is mine

 

so im lookin at around 600 plus installation

 

Yes if you are changing you will have to do them both. You can do the rear first and drive around for a while on it if you are unsure which one you want to go with. Just make sure you don't use 4 wheel drive if you use it say good by to some very expensive parts. And a good overall estimate for everything done and said is around 1400-1500. Not cheap but it will save a ton of headaches down the road.