Ideally it would be nice to get the original gear ratio back in it. On the other hand, let's look at the difference between the two ratios. Someone correct me if I'm wrong but the 3.77means driveshaft revolutions to one complete revolution of the wheels. Therefore apply that to the 3.91. the truck will get a little better milage with the first gear ratio, (3.77) and more power with the second, (3.91). All in all you may lose a mile to the gallon highway with the higher gear ratio. The flip side of the coin is more torque at the wheels and easier take off. IE, less wear on the clutch in stop and go situations. If its not a 4x4 then it's your choice to make but if it is a 4x4, then you need to match the gear ratios front and rear. If there's no tag on the rear end, you will have to have the VIN number run for the ratio or check the gears themselves. I can't say with certainty that Toyota stamps the gear ratio on the ring gear but every other rear gear I've ever seen has it stamped right on the ring gear. Hope this helps you.95 T100 ext cab 6 cyl 5 speed dx 2wd. Bent the rear differential axel housing now both rear tires wearing. Junkyards they ask for gear ratio either 3.77 or 3.91 for the correct replacement. The gear code from my VIN plate is A08A. Will either fit without any problems. Cant find an exact information on my axel code either is it 138mm, 4.11 and 2 pinion. Lost in limbo, Help?
Details,Details..lol
Details for what
Are you asking for details or being sarcastic speed? Lol
