i own a 87 toyota truck thats lifted and i found that the gears mentioned in the article just are not enough for the type of wheeling i do in ohio, so id tried 5.90 and ive had no problems in torque ect as far as the gears , it increased my rpm rainge just above what it would have been if i would have left the stock tires and ring and pinion in .  im happy to say to say my toy has had alot of hard fun in ohio ind and ky.   thanks and good luck with youre toyota