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Discussion Starter #1
how boggy would it be to have 3.42 with 35s. Would I noticed a significant power loss. I plan on eventually getting 3.73s after I save up more money, but that would be a couple of months.
 

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it will be horrible. you want 4.56s with 35s
 

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Discussion Starter #3
what kind of mileage would you get with those gears
 

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Clit and Tire Liquifier
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If you run the calculator 4.10s and 35s will be perfect for cruising on the highway and good mileage 4.56s if you do mainly city driving.
 

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really? well that wouldnt be bad at all, i just dont want to get 35s and new gears if its gunna kill my gas mileage. I figure it will take a hit a little bit though.
 

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gas mileage will go down reguardless because your getting bigger tires, you can somewhat control it though depending on what gear ratio you choose
 

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I have first hand experience with 3.23s and 35s and re-geared to 4.56s and 35s. This is with a 5.3L and automatic.

With the 3.23s it was horrible, constantly shifting in and out of overdrive, no power, wouldn't hold speed, ect.

With 4.56s, I had to get a programmer to correct speedo, brake lights, and make it perform correctly. I average 13.8 MPG according to the on board calculator. I get about 300 miles out of a tank of gas with mostly highway driving. When I pull the boat I get about 9 MPG if I tow @ 65-70.

If you're going to do it, do it right and pay for the re-gear.
 

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GMFS Enforcer
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really? well that wouldnt be bad at all, i just dont want to get 35s and new gears if its gunna kill my gas mileage. I figure it will take a hit a little bit though.
If MPG is a concern for you then don't lift your truck. However, keep in mind that with lower gears you will turn more RPMs, BUT you motor will not be working as hard to move the truck and keep it moving. Your tranny will love you as well.

For the record I have 4.56s, 35s, 4L60E, 305 V8, and I get 13-15 MPG HWY.
 

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pm spence, he has 35s and 3.42s and he's been driving around on them for months
:word:

I drive around town in 3, no big deal. D on the interstate, but I avoid that all all costs. On the interstate, flat or downhill is fine, but uphill at all I won't be able to maintain speed, and I'll have to downshit, which is going to kill your tranny if your constantly doing that. Just ask Aftermath.

As far as MPG...15, but I'm really light on the pedal. If you want to lift your truck, just do it, and get the gears asap. If your concerned about milage...then why the hell are you lifting your truck:imo
 

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I have had 3.42s and 35s for about 20,000 miles, maybe more. But i do alot of highway miles. I bought 4.56s about 6 months ago but i am never home long enough to have them put in. On the interstate, i run alot in OD but anything close to a hill gotta put it in Tow/Haul and push the pedal down some. Tow/Haul or 3rd in town, but it is a total dog in town and the tranny doesnt like it when i force it up to speed. Surprised it has lasted this long.
Spend the money and get gears and an Eaton. U will not be dissapointed from what i have been told...
 

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I just put 33" BFG's on my truck with the stock 3.23 and I went from 19mpg to 14.8 mpg with a 4.8L and 2wd. The 14.8mpg was mostly highway driving. But the reason I got bad mileage was becuse the truck kept dropping back to 3rd gear. Right now the truck is pretty under geared and plan to swap in new gears as soon as I can.

I'm guessing that 33" & 3.23 would be a lot like 35" & 3.42.
 

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Discussion Starter #15
ya i have BFG 33s with the 3.42 right now i get shitty gas mileage. About 13 around town and maybe 15 on the highway if im lucky.
 

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you will get horrible mpg with 3:42s and 35s, you will almost be putting it to the floor at every stop sign, and will be eating your tranny apart at the same time. 4:56s and 35s is what i suggest, you can get away with 4:10s but wont have as much bottom end power. i had 4:10s and 33s and thought it was a good combo, but if i went to 35s 4:56s would have been the way, btw mine came stock with 4:10s and i loved the bottom end power with the stock tires.
 

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I'm running 4.30s on 31.50s until I get my 33s. I'm only turning 2300 @ 70 MPH. On 35s you definately want 4.56s. It's not low geared. Seriously. It's an old mindset from before the days of OD that 4.10s and lower are low geared, especially with larger tires.
 

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i like the way you think. 4.56s would be perfect. 4.88s if you have ANY doubt in your mind that 35s will be the biggest you will run.
:shake: I ran 4.88s with small 35's (about 33.5" tall) and I loved it. Acceleration and performance "felt" better than stock and I got decent mileage. Driving on the highway wasn't bad at all either. Going 70mph, I was just under 2300 RPMs. I had all the power I wanted in the sand too.
 
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