Ok, you guys were pretty responsive on the other questions, now I've got a few more. I'm ordering the truck this week and wanted to run the final specs by you guys. First, a little background: I'll be purchasing the truck, and shortly after I recieve it, it will go into the shop for a 6" or 8" Pro Comp suspension lift, and to be fitted with some 35" tires. I was originally going to order the truck with the 3.73 rear end, but have heard that I need to go with the 4.10 rear end instead due to the bigger tires. I don't need the truck to smoke the tires or have lots of holeshot, but I don't want it to totally be a pig either. What do you guys think?

3.73 or 4.10???

I was told that the Duramax guys can't go with anything bigger than a 31 or 33" tire because they come with the 3.73 rear end, so if you want to put 35" tires on it, you have to swap out the gears in the back??? I don't want to mess with a factory package that is already plenty stout, but want to make sure I order the right stuff on my new truck.

Does anyone know the difference in fuel economy from the 3.73 vs 4.10 gears if all other factors are the same?

Thanks again in advance guys, I really appreciate all of your valuable advice and insight

Ok, you guys were pretty responsive on the other questions, now I've got a few more. I'm ordering the truck this week and wanted to run the final specs by you guys. First, a little background: I'll be purchasing the truck, and shortly after I recieve it, it will go into the shop for a 6" or 8" Pro Comp suspension lift, and to be fitted with some 35" tires. I was originally going to order the truck with the 3.73 rear end, but have heard that I need to go with the 4.10 rear end instead due to the bigger tires. I don't need the truck to smoke the tires or have lots of holeshot, but I don't want it to totally be a pig either. What do you guys think?

3.73 or 4.10???

I was told that the Duramax guys can't go with anything bigger than a 31 or 33" tire because they come with the 3.73 rear end, so if you want to put 35" tires on it, you have to swap out the gears in the back??? I don't want to mess with a factory package that is already plenty stout, but want to make sure I order the right stuff on my new truck.

Does anyone know the difference in fuel economy from the 3.73 vs 4.10 gears if all other factors are the same?

Thanks again in advance guys, I really appreciate all of your valuable advice and insight

like i said in the other area...

if you get bigger tires, it reduces your power per rotation... so technically you should receive better fuel ecconomy and have less towing power with bigger tires... that is untrue because mud tires or oversized tires are genearlly very heavy, and instead of having just a larger wheel you have more weight in every rotation of your tire, and also more friction due to the mud tires...

not sure what size your standard tires are... and not sure what size your 35's will be but granted their bigger, and if your saying the duramax cant go any bigger then 31's (i can assume stock tires are smaller then that...) and if you switched from 31's to 35's that would be the same as changing from a 4.10 to a 3.73... so if i were you i would definatly get the 4.10's or else you'll have a truck that cant do anything...

I'd have to agree with Tim on this one. The fuel economy difference between 4.10 and 3.73 rear gear ratios is almost moot when you're going to be any form of mud tires on the vehicle simply due to their weight. Although you can more easily move larger tires with the larger rear end, you'll of course lose some fuel economy with the swap. And since I'm coming in on this one a little in the dark, I'd have to say that you're going to end up with a nice truck, however; I'm not so sure I'd want to put mud tires on that heavy of a truck (had a friend who sunk his '97 Dodge 3500 4WD cummins up the frame rails one night, it wasn't pretty getting him unstuck).

Sounds like you want to do something like this: link

Maybe contacting that dealer and asking some questions might help you out.

Yeah, that looks about like what he wants to do.