i have a 2002 f150 with the 5.4. i currently have 31" tires but soon ill be putting 35"s on. can anybody help me on what gearing i need to upgrade to or will the stock gearing be good. i believe i have 3.73 gears now.

 

I suggest at the very least 4.10's for those huge tires. More gear would be better ,but 4.10 is a easy to get combination and I guess you are dealing with a 4x4 meaning you have to change both sets of gears.
Alan

 

The stock gearing won't be good when you get your 35's. You need 4.56's just to be near stock rpms.

 

i recomend 4.56 also

 

What kind of cost am I looking at to change my 3:73 to 4:56 on a 4X4 97 F150?

 

I have a question as well. I have a 2000 F150 4x4 Supercrew (5.4 L)
A while back I had 33" mud tires put on it. The transmission just recently had to be rebuilt. Could that be because the tires are not compatable with the gearing system?

 

gauchomike- Welcome ! Total cost of parts and professional installation should be between $1,100 and $1,500. The 8.8" rear being cheaper than the 9.75" rear.

ThunderCat- Yes; possible...taller tires and crappy gears increase the strain on the transmission, especially in long, heavy configurations.

 

Thanks Max! I'm looking to get some bigger tires and a small lift in the future. Now I know to check into a new gearing system.

 

You're welcome ! That's a good idea for several reasons including reliability and performance. Good luck with your upgrades.