According to http://www.rocky-road.com/calculator.html my ideal gear ratio is
4.63's.Stock tire diameter was 27.4 and stock gears 4.10's, Currently running 31's.
Long and behold i found 4.62's but im iffy about running a odd ball sized gear due to the fact tunners jump from 4.56's to 4.88's.

after doing some research,

31's on Stock 4.10's=469 rpm's less than stock
4.56's=152 rpm's less than stock
4.62's=almost dead on stock rpm's
4.88's=70 more rpm's than stock

99.9% of my driving is city im thinking about going 4.88's should bump up my city mpg's a bit.

what do yall think?

 

holey crap.. id just stick with 4.10's but then again i got a 4 liter.

 

regearing is extremely expensive.. as im in the middle of finding out right now. so unless you really need to do it, dont waste your money!

 

I'm looking at $650 gears,install kit and labor. I'm lucky in the fact I only have one axle to regear. I'm thinking if I run 4.88's and its to low ill do a spindle lift and run 33's.

 

4.88's on 31's? What engine do you have? Most guys run 4.88's with their 35's, 4.56's with their 33's, etc.

 

He has a 4 banger. Thats why he needs the gears that low.

 

2.3l,auto trans,4.10's 27.4 stock tire diameter.Currently on 31's which are 3.6 inches larger in diameter. 4x4's go from 31's to 35's with 4.10's stock to 4.88's, 4 inches larger diameter.

 

I was going to run 4.56's with 31's with a 3.0 Ranger.

I'd run 4.56's or 4.88's. Definitely 4.88's if you plan on stepping up your tire size. Maybe even 5.13's.

 

I think it also depends on the axle size in the rear how low you can gear it... I could be wrong. But a 7.5 can't be geared as low... Not sure what you have. 8.8 I think you can only go to 4.88 if I'm not mistaken.

 

I just swapped in a 8.8. They make some crazy ratios for it I saw 6.14's earlyer.
4x4 guys are maxed at 4.88's because of the d-35 in the front.

 

List of gears made by Superior Gear.

Ford 8.8:3.00,3.08,3.27, 3.31, 3.55, 3.73, 3.80, 3.90, 4.10, 4.30, 4.56, 4.62, 4.88, 5.13's 5.14, 5.43, 5.71, and 6.14

Ford 7.5:3.08, 3.27, 3.45, 3.72, 3.73, 4.10, 4.30, 4.56, and 5.13's

 

Ok i redid my math with this handle little calculator
http://www.superioraxlegear.com/calc...re-height.html

When upgrading to 31 inch Tires
Stock Gears 4.10=266 Less Rpm’s Then Stock
Regearing to 4.56's=39 Less Rpm's Then Stock
Regearing to 4.62=10 Less Rpm’s Then Stock
Regearing to 4.88's=119 More Rpm's Then Stock
Regearing to 5.13's=242 More Rpm's Than Stock

When upgrading to 32 inch Tires
Stock Gears 4.10=329 Less Rpm’s Then Stock
Regearing to 4.56's=109 Rpm's Less Than Stock
Regearing to 4.62=81 Less Rpm’s Then Stock
Regearing to 4.88's=43 Rpm's More Than Stock
Regearing to 5.13's=163 Rpm's More Than Stock

When upgrading to 33 inch Tires
Stock Gears 4.10=389 Less Rpm’s Then Stock
Regearing to 4.56's=175 Rpm's Less Than Stock
Regearing to 4.62=148 Less Rpm’s Then Stock
Regearing to 4.88's=27 Rpm's Less Than Stock
Regearing to 5.13's=163 Rpm's More Than Stock