Walter

So anyone got an opinion. I've got 4.5 from rusty's and bushwhacker flat fender flairs. Need some bigger rubber got 31's with not a problem. I've heard I can fit 33's. Feel like could get a bit bigger in there. Also what gearing would be good for what sizes.

K2dark_xj

33's is prolly big enough. though you could prolly do 35's with correct bumpstops. not sure if the flatflares are big enough for 35's. and gearing depends on your offroad/onroad preference. trail dedicated rig, 4.88's would be nice. but on road, I'd say 4.10's would be a happy balance maybe 4.56 if you don't typically go over 55.
i found a handy chart a while ago i'll see if I can find it.

K2dark_xj

found it. yellow is for gas mileage(highway queen) black is for overall driveability(similar to stock tire to gear ratio) and blue is for torque, acceleration(so basically trailing)

edit: picture came out like crap. so heres a link to the website http://www.4wheelonline.com/superlift_tiresize.htm

Rock Toy

Those charts are mostly useless, they are for a 1 to 1 ratio as in fourth gear in an AX15 manual transmission. If anyone uses them you need to multiply by your overdrive ratio for the correct rpm at 65mph.
Manual OD ratio is .79
Automatic OD ratio is .75

Outlaw Star

The AW4 also has a 1:1 gear (3rd) then to figure out the last gear use your formula for OD.

CheapCherokee

yeah, i wouldn't pay attention to those charts. personally, i would gear as low as you can with stock axles for 33s, so 4.88. the 4.0 can run the higher rpms on the freeway all day long, so don't be afraid to gear low. you don't get as bad of mileage as you would think either. while you may be turning higher rpms, you are using much less throttle to do so.

jrm_2011

31's and 3.07 dose just fine on gas

Rock Toy

Yeah, it is for any transmission that has a 1 to 1 gear ratio. I just used the AX15 as an example.

I'm running 4.88s with 35x12.50s and I get about 15mpg when I can run a tank full without doing half or more of the miles in 4wd.

Outlaw Star

Also those charts only apply to a stock engine. A built or stroked engine will require less throttle to turn the tires due to increased power.

Rock Toy

Those charts or any gear ratio chart or gear ratio formula has nothing to do with the engine. If you are running your transmission in a 1 to 1 gear and have 4.88 gears in the differential and 35 inch tires doing 65 mph you will be turning 3045 rpm, it doesn't make any difference if you have a 2.5 liter 4 cylinder or a 454 big block. It is the gears not the horsepower that effect the rpm at a given speed.