I am thinking about regearing my '01 ecsb 4x4 to 4.56 from the factory 3.73. I plan on running 33" tires over the 265's i'm running now. My main reason for doing this is to keep the truck a little higher in the rpm's where it makes its power. It just putters along now just over idle and has no ***** at all! I towed a fairly light trailer for the first time this week and it was shifting like crazy trying to find power. Is 4.56 too much gear? Not worried about mileage, it already sucks, just want power! btw, mods are intkae and exhaust, planning on tuning soon.


GregM

 

I'm taking a set of 4.56 gears out of my Tahoe next week,they are to much gear with my setup no traction at all.I'm also swapping my Auburn Pro for a Eaton posi I'd take $200 for both if you are interested.The Auburn still smokes the tires all the way threw 1st and 2nd gears.

 

I've got 4.10's on a 32" tire and it's a little too much gear for me. If I went to 33" tires I think I'd be happier. There is no shortage of torque or power from 600 rpm's onward with the 4.10's, and an inch more tire would still be okay I think.

 

4.10's would definitely be better on a 33. 4.56 would be good on a 34-35 tire.

 

I run 4.88's and 35's. It's pretty steep, but in reality it's about the same as stock tires (245/70's) and the 4.10 my truck came with. Runs close to 3000 rpm at 75mph, but power for towing is much better. 4.56's and 33's would be about equal to a 4.10 and stock tires, which is too steep for some people. If you want it to be equal to what you had with the 265's just go to 4.10, 4.56 will be much better if you need the power for towing or plan ever go bigger than 33's.

FWIW - My gas milage has always sucked, I have had 4 different combos on the truck since new, 4.10 and stock (245/70), 4.10 and 265/70 BFG Muds, 4.10 and 325/65 Toyo (35"), and now 4.88's w/ the same 35's. Milage empty has always been 10-13mpg on the highway. Towing power and towing MPG improved w/ the gears though since the engine does not lug anymore.

 

it's a bit much, but if you do much off roading you'll appreciate the extra gear.

 

I'd be looking at the price tag more than anything. You have to do the front and rear. My estimates were about $1500+ to do gears in my 4x4.

 

 

i think 4.10's would be a good choice

 

Please note that most of the people who were unhappy with their 4.56 gearing were running some kind of FI. You don't say what size engine you have, but a smaller engine, such as a 4.8, will perform noticably better at higher RPM's that a larger engine, such as a 6.0. Also, it should be pointed out that most vehicles built in the 1960's turned about 3000 RPM at 70 MPH. Overdrive and 5 speed manuals have really spoiled us.