373 or 410
12-14-2010, 05:59 PM
#13
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go ahead and do the 4.10s. If you do 3.73s you will always regret it an wish you went lower (numerically higher). I have 4.10s with the same size 275/55/20 and its not that bad.
12-14-2010, 06:45 PM
#14
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Personally I don't have big rims, but I went with 4.56's and don't regret it. @70 i'm pushing around 2600 but to be honest, it really doesn't suck down that much gas. On my last trip back to KC I averaged 24mpg. Honestly I think that with these gears, it puts a whole lot less load on the trans and engine. And frankly, these 4.8's need all the help we can get for some off the line power. But out of your choices, I'd say 4.10's should do just fine.
12-14-2010, 09:19 PM
#15
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i got 373s n my reg cab awd with a 28in tall tire and wish i had 4.56s 2 help outta the whole these 4.8s need all the help they can get.lol and for on the interstate i figure it will n still pull 18mpg or so at 70.
12-14-2010, 10:55 PM
#18
With a 32" tire not to bad. A 3.90 would be good if your concerned. 3.90 is a great gear.
Currently your at this
@65mph
3.42 - 1650rpm
3.90 - 1850rpm
4.10 - 1950rpm
Mine
@65mph
3.90 - 2000rpm
I have a 3.90 gear, 6.0L, cam, and a 29" tire and get 17-18mpg highway driving 75mph. I retract, I'd run a 3.90 for sure in yours.
Currently your at this
@65mph
3.42 - 1650rpm
3.90 - 1850rpm
4.10 - 1950rpm
Mine
@65mph
3.90 - 2000rpm
I have a 3.90 gear, 6.0L, cam, and a 29" tire and get 17-18mpg highway driving 75mph. I retract, I'd run a 3.90 for sure in yours.
considering i'm 4x4 & have a 5.3 and pulling off about 17-18 highway (going that slow), you should see a couple more than that with 3.90s. but like others said, the 4.8 could use some extra gear to get its lazy butt off the line & up a hill, so i'd recommend the 4.10s
and get a truetrac while you're in there
12-15-2010, 12:05 AM
#19
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ive got 4.10s on 30" tires.. its a great set up for performance and i get 17.5 miles on the fwy driving at 70... and yes im up there in revs. 2300 @70... so with 32" tires i say 4.10s is good.. anyways the more gear the easier u get ur truck moving.. so what ever it takes away in the fwy it gives back in the street.. one thing for another..
the only way to go!!