I have a 98 f150 4x4 with a lift kit and 35" tires. I have not done anything with the gearing yet. Would you recommend changing the gearing and if so what ratio should I use? Also what brand do you recommend and how much will this cost me? Any help will be appreciated.

 

First, what is your stock gear ratio? What was the stock tire size? And what trans do you have, auto or manual?

Steck

 

This is what I have.
5.4L 4x4 auto w/OD 35's and 4.10 gears.

With that said, if you are similar I would put 4.56's in. Especially if you go offroad. I do alot of Hwy driving but Im statring to think the 4.56s would have been a better bet for me because of the OD. Not to say the 4.10's are weak cause they are not. I have Richmond gears and I am very happy with them. Motive is a good gear too. A little cheaper and they are made by Richmond.

 

most likely you will need 4.56 to get close to stock this might put you around 100-200 rpms over stock depending on stock tranny gears and tires but that many rpms over stock would give you better performance and offroad capibility anyway at the cost of some highway mpg

 

Jbird21- Let the guys know your engine size or type of rear differential, so you can get closer estimates on cost and recommended brands.

 

My truck is a 98 f150 5.4L automatic. Im not sure what the gearing is i think it is either 3.08 or 3.55. Not sure on how to find out. The stock tire size is P235/70R16. Hope that this helps!

 

You can get the axle code from the driver's side door jamb sticker. This code can be posted or searched here for an actual ratio. The actual ratio is also included on the second of 2 lines of information on the axle tag, under one of your rear cover bolts. The 5.4 uses a 9.75" axle and the 98 model has a different installation kit than the newer versions. The 9.75" has no ratio between 4.10 and 4.56 like the 8.8 does. The 9.75" parts cost more as well. Yes, I recommend changing gears. If you don't have a LS, I'd install one while the differential is removed. I agree with the others on the 4.56 route. I've had good luck over the years with U.S. Gear and Precision. Changing the front and the rear gears on a 4x4 will be a hard hit on your wallet. Assuming you have a shop do it, you're looking at about $1,200-$1,400 ,plus LS cost, if you add that in.

 

thanks for the help. Im looking forward to getting it all set up and installed.

 

You're Welcome !

 

Bigtruck311, What type of 4.88 gears do you have? I have a 98 Expy with Precision 4.11s and will be going to 4.88s soon with newer tires. I'll be going to the same PJs I have, but in 38x15.50s. So far, all I can find are Yukon gears for my 8.8"-IFS-CV front end and 9.75", 12-bolt rear end. Thanks