GMCtrk, thank you for the input. I was looking for 1st hand experience. I'm wondering though if your dissatisfaction with the 6.0s low end was because of a cam. I short shift my truck and keep it in the 1000-2000 rpm range and it pulls along fine. I'm not too experienced on this yet, but when my buddy with a heads cam LS1 Camaro drove my otherwise similar (except stock heads and cam) LS1 he commented on it having much more low end. A lot of time thats what you give up when switching cams.

 

Mine's still got the stock cam. I am very picky on my a) throttle response and b) highway cruising power. So I'm probably a little more **** about it than most. When I give even the slightest bit of throttle input, I want the truck to go. It went just fine with the 3.42s and had no problem getting up the hills, but the pedal was "sloppy", especially if I had to slow down to 50-55ish, truck just wouldn't move with it being down around 1100-1200 rpms. The 4.10s are so much better. I would not go back even if someone paid me to.

 

GMCtrk- i dont think you can compare your truck to his, he has a 5speed manual.... the transmission has alot to do with it...

subtlez28- so what is your rpm on 5th gear while pulling the trailer? i agree 3000rpm is pretty damn high to be cruising at.... i would shoot for a gear that will get you between 2000-2500rpm on 4thgear, what gear would that be 3.42 or 3.73?

my 2500hd with the auto 4l80e 3.73 is around 2200-2300 @ 70mph... but like mentioned its an auto...

 

Here's an idea, sell your truck and buy mine! Your just up the road from me.

Already has the 3.73's, more power, better mileage (especially when towing), and even though it's an automatic it has the button shifter so you can still pick the gear you want to run while towing.

 

the NV 4500 has a 5th gear of .73. That's negligible from the .70 of the 60e and .75 of the 80e. Also being a manual it probably wont have as much drivetrain loss as the automatic. Having said all that, I still would not swap to 3.42s, but if you want to go ahead. If you needed to pull up a hill or something you could always drop to 4th, and cruise lower in 5th, but I'm not a big fan of changing gears all the time.

 

GMC, the point of this swap is so I can pull in 4th all the time. The overdrive gear is weaker.

 

Do the 3.42's, intake, cat-back & custom tune with your stock size tire and you'll be A-O-K in my book!

 

Well, the 3.42 Yukons have arrived. The truck goes in for surgery on monday!

I'm planning on going slightly taller tire also. I'm leaning heavily toward 285/70/17 Nitto Terra-Grapplers (32.7" tall - stock 245/75/16s are 30.5").

 

You might want to drive it with the 3.42s before you put the taller tires on it.I'm wanting to go with 4.56s with my 285s

 

I agree. Going from 255/70/16 to 285/60/18 made a huge difference on my truck - in a bad way