Tell me about it! That's been my fight from day one. My engine makes plenty of torque (~400 at the crank) but the transmission wants to drop the RPM down really low and make very little power. The O/D button on the shifter is your friend, don't be afraid to just keep it off and let it turn at closer to 3000 RPM. Also, keep ECT Power on non-stop, every day. It does make a difference. That's essentially what I'm after with the regear, making 4th gear closer to 3rd. I made this graph a while back to visually represent each gear and the top speed of each. Look especially at how the 5-speed transmission is geared and how much more torque multiplication it has due to shorter gears. The red line is our speed governor.

That graph is awesome! What gearing is shown with the 5 speed transmission? What rpm's did you use for the top speed in each gear?

Awesome! Looks like the 5.29 ratio would give you something similar to the 5-speed without the overdrive gear. Would be interesting to hear from the 5-speed guys about how they'd feel driving without their fifth gear.

Wow, thanks again for this recommendation! I had some time to look under the hood today and sure enough, there was a good deal of slack in the throttle cable. It seems the rubber bushing where the cable connects to the accelerator petal was split/destroyed. I tightened the cable via the adjustment section near the throttle body but haven't had a chance to test it out on the road yet. Assuming everything runs okay, I'm now wondering if it's even worth the hassle of replacing the cable.

Called it! Mine had the exact same problem. I adjusted it for now. I have a new cable sitting on the bench whenever I get around to it.

Seriously though. Healthy plugs, good wires, clean air filter, throttle body and trans cable adjusted right make all the difference in the world.

Oh, I forgot that part. It's 4.10 gears on the 5-speed. Max RPM is 5500. I realize that a 5-speed can rev higher but to keep the data consistent I used the auto redline limiter. There's absolutely no power above 5000 RPM when stock anyway.

If you are gonna bust the diffs open anyway go with the 4.88's.. and you can use a locker in the front as you said in the snow..just have to be mindful of slip.
Just repaired locked Tundra that split front diff w/ARB it was ugly!!

So just a quick update. I dropped off the 4runner at the shop this morning and went with the 4.88 ratio. Thanks again to everyone who chimed in on this thread to share their suggestions and experiences. Now I just need to figure out how to properly break in the new gears in a short period of time!