I know it has been asked but after searching I couldnt find the answer so here it goes "again". I have a 2003 screw cab FX4 with a 3 inch body lift. What is the largest tire size I can put on this truck? I have 17 inch rims. ALso at what size tire do I need to consider getting the gears changed?

 

Ive got an 02 FX4 3"body, etc, etc...I took my 17"rims off put on 16" american racing rims and put 315-75-16s, (35s). 33s are the biggest I think you can put on your stock rim. I am considering a gear change 3.55s are terrible anyways...If you go that route I would consider a 4.10 or 4.56. Still keep in mind your effective ratio with the larger tires even with the gear swap...ex: 4.56 with 35s closer to a 4.10 gear maybe alittle taller. 4.10 with 35s, closer to an actual 3.73 or so!

 

I've always heard 35's fit with a 3 inch body lift on 97-03 4x4's.

I plan on doing 35x12.5x17 BFG MT's on my stock wheels when these stock size Nitto Terra Grapplers are worn out.

 

with a 3" body only you can not fit 35's. You need 2.5" keys