what gear ratio should i choose with 285/75/16

iluv_mud

iluv_mud

Active Member
Joined
Oct 23, 2007
Location
Asheville
i have a 1998 ford f150 the truck has 3.55 gears but with the tires that are on it the truck has no power, i know i need a re-gear but what should i swap in. (btw it has the 8.8) the truck sees a lot of off road use so i've been looking at 4.10 or 4.56 a 4.30 would be perfect i think but i have not found a 4.30 for the front diff
 
I run 295/70/17 Nitto Terra Grapplers on my hemi-equipped 2003 Dodge RAM 1500 with the stock gears. I'm pretty sure the stock gears are 3.55. I have no issues whatsoever, plenty of power. I'm not sure what size engine you're running, but the 4.10 would be more than sufficient. Are you planning on doing a lot of highway running? Might want to step down to a 3.73 if so.
 
My Powerstroke does fine on 285's and 4.10's. :D FWIW I run about 2400rpm's at 70mph.
 
you shouldnt have that much of a power loss from only increasing tire size that much. Maybe you have a problem under the hood...
 
i dont plan on doing much high way driving i have a dd for that its a 4.6 v8 automatic im also planning a 3 inch body lift and will be stepping up to 35s. that is also why i was considering the 4.30 if i could find a front R&P in 4.30 and my truck unfortunatly doesnt have a tach so i cant tell what my rpms are cruising
 
if it is not a DD you should go steeper than a 4.30. Like 4.88, you would be impressed with the performance gains, and it would change your crawl ratio a good bit which is good for your automatic.
 
the crawl ratio is one of the factors of the steep gears u cant get t case mods for my truck. the truck currently doesnt run know thanks to a broken diff and when it does run it wont get driven daily (trying to push the limit of what can be done with ifs) I also dont have the time off or the tools to do the gear swap and the detroit locker i plan on putting in the back so i would like to know if any one knows a good4x4 shop in wnc or someone on this forum who could possibly install these for me will pay
 
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