Just went from the stock size tires on my 87 4runner to 31's and my speedo is off. Anyone know which tooth # gear i need to bring it back in sink? Toyota is no help imagine that!

 

I don't think Toyota offers different speedo gears (like Jeep does). Best bet is to just regear the diffs to 4.56 and be done with it. After the initial cost, you'll like the power you get back from doing this, something a speedo gear can never get you.

 

They do offer different speedo gears, but power is a complaint!!!! This might be worth looking into. What are we talking about in initial cost and is it that big a difference?

 

What does that gear change do to your RPM range? I run about 3000 at 70mph.

 

A change to 4.56 gears will bring the rpm range back to what it was when you ran stock size tires. As such, your speedo will be correct again and your power will be closer to what it felt like with the stock tires or roughly a 10% gain over what you have now. Gearing changes are not cheap but they are the better option in the long run, especially if you plan on keeping the 31" tires for any length of time.