I was reading the past post on gearing but I would like an explanation of gearing. So what would be the difference in drivability between the 4.10's and 4.56's for me? 5.9L 4x4 285 75 R16 all terrain tires 46RE Transmission 3.92 gears now.

My goal is to help the trucks acceleration, it is such a dog now. It shifts way too soon, goes into overdrive at 35mph when going up hill and flooring it does nothing. In overdrive going 75mph im at 2,000 rpm

I dont tow, or race or anything like at, just looking to make it more practical for driving everyday. I live in a very hill ridden area so its sluggish all the time, bums me out.

thanks all

 

With your current tire size (285/75) 4:10 would be the best choice. However, 4:56 would give you more torque off the line but would also raise your rpms to about 2650 on the HWY at 75. If your ever plan to go up a tire size to 35" or larger get 4:56's. If not id go with the 4:10's.

 

jlake pretty much nailed it. Given you already have 3.92's though, I don't think the jump to 4.10s would offer enough benefit for the cost involved. (even if you can do the work yourself.....)

If you tow a lot, then maybe.... but, like he mentioned, if you plan larger tires in the future, 4.56 is definitely where it's at.

 

Top comment is pretty much spot on. Another thing is if the truck is your daily then 4.56s would totally ruin any kind of MPGs your getting now, if that matters to you.

 

It depends on the speed you drive the most. If you spend a lot of time at 75 I'd keep the 392's or get 411's. If you're in the 60-65 range get the 456's. They will definitely help acceleration. My daughter's 87 Chevy has 456's with 33" BFG All terrains on it. If we lived where we ran 75 mph, we'd maybe consider 35" tires next time. It works great where we live. That's the hardest part, none of us know what your daily drive really consists of, or how you drive. A tuner might help with your shift points.

 

How much worse can it get haha? Im already rocking an average of 10. Depressing....

 

You should be able to do better than that.... How old are your O2 sensors?

 

I assume originals. I have the Magnaflow CAT system on my list to buy along with all new sensors. Right now it has Pacesetter shorty Headers and a Magnaflow Muffler. I keep putting it off because the CAT's come to $740 alone, makes me real depressed to think about what else i could buy with that that would be waaay cooler.

 

Anyone here have the 5.9 v8 4x4 with 33's and 4.56's that can give some input on average mpg?

 

I have 33's, and 4.56 gears, and a 8.0, and I average around 11......

You should be able to find cats cheaper than that.....