Hey dude, I just went from 3.42's to 4.10's and have the 275/50/17's on my truck. I love the setup and am very happy with it.

 

hay la cuerva what rpms is your truck at 75mph with the 4.10's and where did u get them from?

 

hey cuerva what are your 1/4 mile times if you dont mind me asking?

 

It's running about 2350 to 2400 RPM's at 70 and about 2000 at 55. Big difference than the 3.42's but a whole lot better. It downshifts at about 10mph lower now when floored (at about 25 and 55 vs 30 and 65).
Got the gears from Summitt Racing (Motive Performance).
I ran a 13.9 with my 3.42's and a 13.8 with the 4.10s. Both times used the 270/50/17 Nittos at about 20psi and no traction all thru 1st and 2nd. I am getting a 3000 or 3200 PI stall, just trying to make up my mind as to which one to get.

 

4.10

 

i got 3.90's and much better than the 3.42's dont know why chevy makes them with that low of a gear. i run the original american general tire on 16's and at 70 the rpms are 2200, go with 3.90's or 4.10's you will not regret it.

 

I bet the MPH in the 1/4 dropped with the 4.10's though

 

4.10

 

yes it does drop a little, it all depends on what you want (lower and better times or higher mph's. In my case traction is a big factor right now withtout slicks, less traction with the 4.10's.

 

The only thing now is that with the 4.10s and since i have a 4/6 drop, I do have some vibrations at high speeds over 110 mph (not business being up there too often). Need to install the 4 degree pinion shims (alrady have them) for piece of mind. Just need to get around to it.