I had 33's and stock gears in my 85 toy I found it a lot slower accelerating and trying to spin the tires in gravel and mud, with 31's and stock gears i could spin the tires in second and had no luck spinnin them in second with the 33's but I would still run 33's over 31's anyday, and about 35's and stock gears I test drove a 85 4runner set up that way and i could hardly get out of first going up the littlest hill because it had no power, I recomend never doing that.
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Sold 85 Toyota extra cab 4x4 2" lift 33" BFG M/T with lots of tire rub!
Wanted 84/85 4runner, needed a few more seats less rust, and a beter FRAME.