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Discussion Starter · #1 ·
My rear end is in bad shape, its come time to regear and ill be getting a new trans very soon as well. Everything is stock right now(3.73 i think?:think: )

Current tire setup is 325/60(33x13.50) on 18x9 wheels, truck will be getting more lift and 36's purhaps in the future, if i have it that long. I do a LOT of pulling and tons of highway driving(300-500 miles a week). I would like the truck to be able to stay in overdrive on the highway(downshifts all the time for the slightest inclines). Ive been told to do 4.10 but im not sure.

Any help would be appriciated.
 

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GMFS slowest truck :read:
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ATLEAST 456s. you are thinking about bigger tires already...gear it once and gear it for them.
 

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EMBRACE WHAT'S LEFT
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600 labor front/back depending on where and what gears you get 450-650 for gears and install kits
 

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Resident *******
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a local place gave me a quote of 1600 with a detroit tru trac for 4.88's.. so somewhere around that.. And yea man if u plan on going 36's def go 4.56
 

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Swamper Brotherhood
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Yea man 36s would be perfect for 4.56. also just a word of adive, I drove around on a g80 that was going out for a year. when it finally went out it cost me 3700 in repairs. I had to replace my ring and pinion, carrier, went with a true trac, had to replace ujoints and transmission also. everthing went all at once with the g80 grenading. If your rear end is gettin bad i'd fix it before it breaks. Also if you need a new trans go with the gm factory remanufactored. 3 year 100k mile warrenty. Also if you want to find out your stock ratio look on your code tag on the inside of your glove box. You might have 3.42 gears if it kicks in and out of od. check for the code
GU6(3.42) or gt4(3.73)
 

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4:56s for sure, with the 33s ull have great low in power, but if u put 36s later on you will be like a stock setup. 1000-1200 for just gears and labor, and u can add more if u put in a locker of some sort, which i would. also it would be a bad idea to upgrade to a 14SF
 

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Discussion Starter · #9 ·
If i drive for a while with 4.56's on my 33's will my milage be conplete shit? I drive this thing A LOT, and will be going to the Ozarks(9 hour+ trip) at the end of July pulling my boat.

And yes, i am going to fix it before it gets worse, it is really bad and slams and knocks around like crazy, tranny is shot too and is being replaced as well. I have parked my truck until i can figure out what setup i am going to run.
 

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If i drive for a while with 4.56's on my 33's will my milage be conplete shit? I drive this thing A LOT, and will be going to the Ozarks(9 hour+ trip) at the end of July pulling my boat.

And yes, i am going to fix it before it gets worse, it is really bad and slams and knocks around like crazy, tranny is shot too and is being replaced as well. I have parked my truck until i can figure out what setup i am going to run.
4.56 on a nine hour trip....:insane: have fun lol that might not be the best on gas for ya... idk what I would do dude
 

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GMFS slowest truck :read:
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4.56 on a nine hour trip....:insane: have fun lol that might not be the best on gas for ya... idk what I would do dude
how you drive has a lot to do with it...most people wouldn't think my gearing set up is too great, SMALL 36s and 5.13s, but as long as you stay the speed limit on the highway (shouldn't pass it anyway if you are worried about mileage) then its not gonna hurt anything.

GM and other automakers have gotten us into thinking that anything below 3.73 is deep...its not...3.42s and higher should not be an option on trucks, period. 3.73s are ALMOST deep enough for the stock sized small tires, but oversized tires at all (even 265s) 3.73s isn't ideal for if you have to tow at all.

you will have to make the decision on whats best for you. you know how you drive and what you drive better than any of us. i, personally, rarely take mine out on the highway and don't mind being slightly overgeared, but would hate to be undergeared at all...

small 33s and lots of highway over 70 mph, 4.11s, big 33s and keepin it the speed limit, 4.56s without a doubt.
 

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Discussion Starter · #13 ·
I think ill go with 4.11. I dont know when, if at all(i dont think this truck is worth anymore money) I will lift it. And with racing and everything else this truck is on the highway constantly at 70mph+ I have only had the truck about 4 1/2 months and put 12k miles on it...
 

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If i drive for a while with 4.56's on my 33's will my milage be conplete shit? I drive this thing A LOT, and will be going to the Ozarks(9 hour+ trip) at the end of July pulling my boat.
That's what I'm running. my 35s measure 33" and I've got yukon 4.56s with a yukon lsd. On the highway, i get about 13 doing 75 mph. If i was really concerned about the gas mileage, i'd drive 65 and avoid passing people. In town, it pulls great. I haven't pulled a trailer yet, i will in august, but there's plenty of power on tap in town.
 

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Discussion Starter · #16 ·
My truck already gets 12-13mpg at best. Even when i had little 285's all highway it was only 13.5. That is why it is so hard for me to believe everyone who gets such great milage, If this truck drops below 10mpg its gone, the reason i dont drive my Dodge is because it averages about 8-9mpg.
 

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My truck already gets 12-13mpg at best. Even when i had little 285's all highway it was only 13.5. That is why it is so hard for me to believe everyone who gets such great milage, If this truck drops below 10mpg its gone, the reason i dont drive my Dodge is because it averages about 8-9mpg.
how fast do you drive on the interstate?

I pull 18 mpg+ crusing at 65 in 3rd at 2100 rpm's on a hilly highway and I've got small 35"s and 3.42's still.
 

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The Green Seal
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going from 3.73 to 4.10 is a waste if you ask me, go 4.56 and dont look back

with that said... mmm 5.13s
 

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My truck already gets 12-13mpg at best. Even when i had little 285's all highway it was only 13.5. That is why it is so hard for me to believe everyone who gets such great milage, If this truck drops below 10mpg its gone, the reason i dont drive my Dodge is because it averages about 8-9mpg.
my truck completely stock except for a borla muffler got 20 mpg doing 70-75 on the highway.
 

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Discussion Starter · #20 ·
My truck is bone stock with 33x13.50 tires. I usually only run 75-80 on the interstate and about 65-70 on the local highways. The best i have ever gotten was seriously not much over 13, that is why i dont understand how you guys do so good? My truck runs perfect, is maticulously maintained and I still get shit for milage.
 
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