go with 4.56 gears that what i have and it was one of the best things i have done to the truck, i used yukon gears. i also put in a eaton posi at the same time, did everything my self so it was just the cost of the gears and posi for me

 

4.56s for sure that's what I have. My gears are Genuine Gears, and I have never experienced this mysterious "whining."

 

Does anyone know how long/difficult the installation is for replacing the front and rear gears? Because i have auto mechanics class at school so i have all the equipment needed i just want to know if it would be possible for me to do it myself.

 

I got 4:56's too, only way to got with 35's. I paid $1350 to have it done. I could have done it myself but I would have had to do it in my driveway and it would have been a real pain.

As for the time doing it? My shop had my truck for a day and a half, the rear end is the easy one. The front is the pain, A arms and all that stuff has to come off to get the front 3rd member out.

As for doing it at your school I say go for it, that would be a great learning experience for you. Its really not that hard

 

I know the thread is a month old but if it helps, I've got 4:56 gears with 35's and paid $531 for install but my truck is only 2WD to. If you go to 4wheelparts.com and click on tires..there will a an option for a gear ratio chart that will tell you exactly what you need depending on what you use your truck for..hope that helps for any future problems