Going from 4.56 to 4.88s wouldn't be worth the $$. You'll get a little more power but not $1500+ worth. I would do 5.29s if I were you, but I don't have experience regearing with a 3.0. You can use an online gear ratio/rpm chart to see about what your rpms would be at freeway speed. I hit 3K rpms @ 80 mph with my 3.4 and 4.88s/33.5s.

 

My dads 79 4x4 had 3.90s

 

Not from the factory it didn't.

However, I was mistaken in saying that none ever did. Since I initially wanted to give you the benefit of the doubt, I did some research to see if what you're stating has any truth to it. Well...it doesn't.

In 1979 and 1980 only one final drive ratio was offered in 4x4 trucks. Which was 4.38s.



1981 was the ONLY year that 3.90s came stock in a 4x4 truck(prior to 1996).


1982 was the only year 4.11s were offered in 4x4 trucks.


1983 was the first year for 4.10s in a 4x4 truck.


From 1984 to 1988 only 4.10s, or 4.30s, were found in 4x4 PUs and 4Runners.


Later years came with the other 2 stock final drive ratios for 4x4 trucks and 4Runners, 4.56s and 4.88s(again, prior to 1996).

5.29s and 5.71s aren't stock final drive ratios.

Thanks for challenging me on that. Now I know even more than I did on the subject!

 

4.56 gears on 33's isnt that bad, i can drive up most hills in 4th except steep ones

 

Using the off-the-cuff "1/10th of a gear = 1"" gear formula...

Your theoretical gear going FROM 31's TO 33's will net you a 4:36ish gear.

So, now throwing 2 10ths on 4:56's = 4:76... So yeah, 4:88's are closer, but you've got a 5 speed, not an AT.

That right there is a HUGE difference. I'd say you'd hardly notice.

Plus, you've got more torque than an RE to make up for the loss of .20 of your gears...

It's up to you. I'd say if you feel you're a tad over-geared now, you'll be just fine only going up 2" on the tire. (only + 1" in ground clearance BTW)

Now, 33/10.50's an aluminum wheel, and I'd say you'd hardly notice.

 

Update, I am still running 32" tires with stock 4.10 gears. I now run with the "ECT" button on so it will downshift a little earlier when approaching a hill. BUT, overall I would still like to stab myself in the eye with a fork when driving on the highway through the mountains at 68mph with the cruise control set. But, I think changing to 4.56 or 4.88 gears would still be cheaper than the medical bills from the eye doctor. Arrggghhhh

 

so... I plan on eventually running large tires on my rig, but as of now and for the near future it will have 31 & then 33's on it... I am planning on getting lockers done, and figured while everything is torn apart, i would regear... should I just gear to 5.29 (up from 4.56 w/ 31's) and be done with it so that when the time comes for large tires i wont have to re-gear? An SAS is also in the cards down the road... just wondering