I am going to get 33" tires on my ranger, what gearing should I get for the back??

 

4.88 if your transmission is a manual 4.56 if it a automatic

 

With the 4.0, 4.56 gears would be a good match. Just a heads up, you need to change both differentials on a 4x4.

 

Yes, +1 ^^^
You must change ring and pinion on BOTH Axles, can't just change the rear

Look at the label on the drivers door edge and get the AXLE code, and stock tire size
Then look here: Ford 7.5 & 8.8 Inch Axle Tag & Door Codes

Then go here and enter in the data: Gears needed after adding larger tires

New tires are 33"
Stock tires are 29"
Current ratio is 3.73

So with 33" tires the actual ratio would be like driving stock tires with 3.28 ratio, so much less bottom end power, but better highway MPG and top speed

1996 Ranger still uses speedometer gear in transfer case so after a tire change you can recalibrate speedometer by changing this gear

S

 

also to be noted !!!!
because you do not have a strong gear box compared to full size pick-em-up trucks

you would be better off installing 5.13 ratio gear sets

this high of a gear ratio will take some of the stress off of the transmission and place it on the ring and pinion gears