What diff?

[leeso]

I'm running 4.10 diffs and 33inch tires and at 100kph or 62mph my engine is doing 1950 rpm and using heaps of fuel. I want to drop the revs down and don't know what diff to go to a 3.73 or a 3.54 and maybe 35's. If you can tell me what you are running may help me make up my mind thanks.

 

[Supershafts]

If you go 35's i'd keep the 4.1, if you leave stock tires i'd stay at 3.7

 

[Amish Elegance]

Unless you tow heavy, and I mean heavy, I don't see the need for the 4.10's; especially given the sacrifice in mileage at any reasonable speed.

With the low end torque these engines are known for, unless you're running a large single, its more than enough to get all but the biggest loads out of the hole just fine.

I rolled 35's and a 64/13 single, towed 5k regularly, and never once wished I had lower gears. $.02

Unless you're a stop and go city delivery truck, get the 3.73's and don't look back. If you're putting mostly highway miles on; hell, you might even want to look at a set of 3.42's.

 

[leeso]

I might put 35s on and see what the difference is and if its not much better I'll look at the diffs. I'd like to get it doing around 1500 rpm.

 

[Bshaips]

My buddies 03 has 4.1 gears and 35 mtz's and he runs 70 mph at 2k. The speedometer hasn't been corrected for the tires tho.

 

[Tnspark82]

I have several friends with 3rd gen trucks. We all agree for a local work truck 4:10,a are the way to go. Now for highway and towing go 3.73. If your just on the highway or towing nothing more than some four wheels 3.55 or less. I personally have a 2gen with 3.55 and that's the truck I now use to travel with.

 

[kingshado]

I have 35's and 3.73s with 48re and I would not recommend the combination for towing unless you have the stock he351 or a similar small quick spooling single. Anything below 65-70 is just a pain. Switching to compounds for this reason.