I am considering possibly re-gearing my axles in the future. I am currently running treadwright guard dog 265/75/16 tires and am ordering a 3" terrafirma lift with a new steering stabalizer and Brake lines. With the 3" lift it will leave room for possibly bigger tires (33") and I know that re-gearing would be beneficial as I would have stronger gears, more accurate speedo and less of a mpg drop. Any thoughts/experience on this? I also plan on a 4.6 conversion. This truck is a keeper for me so I don't mind investing the money in it, as I am not planning on replacing it with anything else unless (God forbid) it ends up in an accident and gets totaled. I have much more planned for it in the future little by little.

 

First, you will not get stronger gears unless you buy the new 4:14 gears offered by Bill at Great Basins Rovers in Salt Lake City.
I run 4:11's with my 265's and even with 33" tires that gear ratio range will be great. I would though suggest you throw lockers and axles in as well to handle the extra torque you will have with those 33"s.

 

Found a little information to back my post up.


4.10 (10X41) 41 tooth ring gear

4.11 (9X37) 37 tooth ring gear

4.12 (8X33) 33 tooth ring gear

4.14 (7X29) 29 tooth ring gear

Below is an actual comparison of the respective ring gears showing the significant difference in ring gear tooth size



Here is the approximate durability increases (shock loading) as calculated by Gleason Corporation.

4.10 to 4.14 +30%

4.11 to 4.14 +20%

4.12 to 4.14 +10%

 

With a 3" lift and Guard Dogs you will have the exact set up I am planning on. Post pictures when you get it done!!!