I have 4.88s with 9.75 diff on my 150 4.6 with 35s on 9inch lift and what a difference in acceleration. Down side is the lack of fuel mileage. Went this route to make this truck better for towing.

My 250 I had it ordered with 4.30 knowing a 6inch lift and larger tires were being installed. Have 37s on now and truck drives well. 40x15.5 are going on shortly with these 37s going on 150. Cant wait to see how the 4.30 handles these larger tires.

 

Nope. You need the install kit too. Bearings a good idea. Have you ever set up a ring and pinion? Takes special tools, micrometer, marking compound to check mesh pattern, etc. it's not a bolt in affair. Plus I'm pretty sure you need new carriers to go above 3.73. Call Randy's and find out for sure. I would but parts from autozone, use Randy's because they're experts and will get you the stuff you need. Also see if you need a tone ring for the ABS for your year.

I would have a shop do it though. If it's installed wrong you'll get gear whine or wreck your gear set and you wasted all that time and money.

Diff Wizard