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As the tittle says guys, I am trying to decide between 4.10's and 4.56's. The truck is a 01 QC, v6, 5 speed, 4x4..Right now the truck has 265/70/16's and 3.55 rear gears. I would like to step it up to 265/75/16's, Im doing the gears anyways since the truck is gutless. I cruise at 70 which if im right, is right around 2500 rpms. Opinions? A dana trac lok is going in at the same time.
 

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I know a bunch of drag racing Rams who love the 4.56's, but I personally would do the 4.10's. If you were strictly mudding it then I would say yes 4.56 or even the 5.13's. But those are probably going to kill the mileage you get on the highway.
 

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i have a 01 dak V6 3.9 auto 3.55 gears. in town driving only 35-50 MPH was getting 8-9 MPG i DO drive hard. as i wasnt getting power OR MPG i went to 4.1 gear and pow-loc. and didnt need to adjust the speedo. MPG went to 11-12 MPG. what happened was it will go into O.D. at 30 MPH. and the 4.1 gear had good power at low speeds. at 30 MPH the tach 1300 RPM. driving the high way i would not run 4.56.
 

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You can't really compare a R/T to a 4x4 V6 when talking gearing. Also you have to look into what gears are even available for your front axle before worrying about rear axle. When changing gears on a 4x4 you have to do both front and rear at same time, and from what I remember, there is very limited option for the front axle, which will pretty much dictate what you will be able to run in the rear.

As for my opinion, stick with the 4.10s if you can, especially if you do a lot of highway driving. If you have 3.55s now they will be a huge improvement for you. Much like a R/T going from stock 3.92 to the 4.56 gears.
 

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We recommend going a little deeper than the gear ratio calculator would tell you to go to make up for oversized tires. In an effort to improve fuel economy, late model overdrive transmissions are geared very high which means RPM’s are very low on the highway. When even a slightly taller tire is installed the RPM’s are reduced below acceptable levels that the engine was designed to run. This causes constant shifting out of overdrive, sluggish acceleration, poor economy and rapid wear on the transmission and other components.
 

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You can't really compare a R/T to a 4x4 V6 when talking gearing. Also you have to look into what gears are even available for your front axle before worrying about rear axle. When changing gears on a 4x4 you have to do both front and rear at same time, and from what I remember, there is very limited option for the front axle, which will pretty much dictate what you will be able to run in the rear.

As for my opinion, stick with the 4.10s if you can, especially if you do a lot of highway driving. If you have 3.55s now they will be a huge improvement for you. Much like a R/T going from stock 3.92 to the 4.56 gears.
totally aree,before my sas I put 456 in. On the freeway it would rev and that was with 33s, 456 would be good n the city. Id do 410s, more freeway friendly
 

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Bump bump.
Super late to this thread but I'm installing 4.56's in my truck right now, so thought I'd comment. I have an '03 QC 2wd with 4.7 and auto (45RFE?). The factory gearing was 3.55 in the LS 9.25". Stock tires were 29.5" (245/70-r16) but I run 30" (255/70-r16) on the rear or 30.5" snow tires in the winter.

Okay, so a few months back I had the rear end completely rebuilt, and swapped the 3:55's to 4:10. I was going to use 3:90's, but just "went for it" and hoped the 4:10's wouldn't be too deep. Well, they were Not too deep, and now I'm pulling them out. I was surprised at how little difference I could feel. I noticed it at first of course, especially on steep hills in my area, but quickly got used to it. Nothing spectacular. Half of my morning commute is freeway, and with 4:10 I'm turning 18-1900rpm at 60mph. (Our family wagon Sienna turns about 2500 at the same road speed). I'm expecting the 4:56 to give me the oomph I'm looking for, and turn about 2400 rpm at 60mph. If its a little higher that'll be fine. I often turn the OD off if I'm not on the freeway.

BTW, I have been driving this truck daily since 2008, and know it well. I am posting this because when trying to research this myself I have found many Dakota owners on many sites saying that anything past 3.90 is rediculous and will blow up your motor. Def not the case with 4:10, I'll let you know how the 4:56 works out.
 

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If you say you didn't notice much of a difference between the 3.55 and the 4.10, then you will have basically the same difference between the 4.10 and 4.56. You really want to shock yourself, go back to 3.55 and realize how much of a difference the 4.10s made. But I'm sure you will be happy with the 4.56.
 

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I know what your saying. I definately felt it at first, but got used to it quickly. I have a Superchips 91 program and it really doesn't feel like much. Unless I set it back to stock- then it's a real dog! Can't believe it was ever that "slow". I'll post up how the truck runs after a few days driving.
 
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