Regearing from 3.73s on a '93 3.0 for 31s

[Str8sixfan]

Obviously you can use the gear calculator in the tech section. Someone once told me this rule of thumb which is where I start at for a minimum:

For each 1" taller tire you go, it's essentially like knocking off .1 from your rear gear ratio. So if you wanted to keep it close to stock, and again assuming you're going from a 235/75/r15 to a 31...

28.8" tire to a 30.8" tire...

So that's 2", and .2 you'll need to make up. That's a 3.93, so 4.10s are the closest thing.

Now if you use the gear calculator it will probably tell you something steeper, on the high side of that 4.1 figure.

In conclusion 4.10s could be worth it for you, but if you think you'll ever go bigger with tires, you don't want to have to do it all over again, and go 4.56s. More than likely you won't regret going 4.56s, but if you spend a ton of time on the highway, maybe not.

 

[locked ranger]

Sounds like it's a resounding "Yes" for the 4.56s
Thanks for all the help guys, ya'll are great!

You can get the gears set up alot cheaper at some shops by just taking them the axle and 3rd member if your set up where you can pull the rear axle and front 3rd member and take them to a shop. its a good bit of labor for you but it is an option if your cash is low. just ask the shop for a gear set up price then ask how much cheaper if you just bring the axle and 3rd member. its less labor for them, plus your truck wont be taking up a bay.

 

[dirtystanchez]

I have an 87 SC, 31's, with 2.9L and I just went to 4.56 gears. I too contemplated 4.10 vs 4.56 but in the end, if you look in the tech section on the RPM chart, 4.56 gears won't rev much higher in the rpms. I can tell you I'm happy I decided on 4.56s. The power is night and day, and I can go up to a 33s in the future without losing too much.

Go with 4.56s, you'll be happier. I too live in CO and going up i-70 was a PITA. Now, it's not so bad.

Taken from the 'Sticky' at the beginning of this section...........
What's the best gear ratio to have for "x" diameter tires?

The following ratios have been optimized for both power & MPG:

ALL RBV engines EXCEPT 4.0L V6:
27" tires = 3.73
29" tires = 4.10
31" tires = 4.56
33" tires = 4.88
35" tires = 5.13

4.0L V6 engine:
27" tires = 3.55
29" tires = 3.73
31" tires = 4.10
33" tires = 4.56
35" tires = 4.88
37" tires = 5.13

For very early Rangers without overdrive transmission:
Use 4.0L chart

 

[Dies A Lot]

Look at this and just see if you want to try it. Me , well, the shop can do it and I don't have to worry about it.

http://www.angelfire.com/theforce/5ohcpa/cpa5ohtech001.htm