I picked up my truck on Friday afternoon after getting 4.56 gears installed. My first reaction upon driving it was that I had wasted my money: I didn't feel much difference at all. As I started putting miles on the truck, though, as the gears got broken in, you could really start to feel a difference. It's like a whole new truck.
I drove it pretty easy this weekend, but even under light acceleration, it's a nice difference. It feels like the motor isn't working as hard, and it might be in my mind, but the trans feels like it's shifting easier.
The RPM difference is susbstantial on the highway. With the 3.55's, I was doing 2000 RPM at 70 MPH, now I'm doing 2000 at 50 MPH. The truck shifts into overdrive at around 40 mph now, instead of 50, which is really nice. I haven't gone through a full tank of gas to calculate my gas mileage, but I'm guessing I've lost 2 mpg on the highway, and maybe gained 1 around town/ in the city type of driving. I'll have to go through a few tanks and see how it is. With the 3.55's, I got 10-12 no matter how I drove it, though I'm generally easy on the truck.
So, I would definitly reccomend this mod to anyone who is considering it, if you have the money to spend on it. I think it was well worth it.

 

Congratulations! I know many of us are envious of your truck now. Would you mind giving a ball park number as to the cost? And what brand gears you bought? Thanks.

 

And what did you do in the front? Did you use the thick gears, or was a new carrier the only option?

 

Total cost was $1578.78, which also included a new axle joint on the driver side. They used Motive gears. The guy that did the installation preffered to use a new carrier, instead of the thick gear.

 

Thanks for the info.

 

Congrats!!! Got to the truck clubs section, join the 4.56 Gear Club and put the badge in your sig...

 

So, how do I add the badge to my sig?

 

When you guy talk about a new carrier, do you mean a whole new differential housing or the part that the ring gear bolts to?

 

Kinda like that. You can add the text if you want or uncenter it, I just plugged it in, easier to do that then explain how...

 

Rub it in my face some more! Once I get 2k together and than 1800 for the new tranny I'll let u know.