I have a 99 5.3 with 3:42's and am looking to go to 4:10's. My tire size is 255/55/18. If your wondering about the tire size, it's on a 4/6 drop. 4:10s good choice? Any opinions.?

 

I have yukon 4.11's with an eaton posi. I love the launch! Although it will drop your top MPH, It'll scream compared to what you have now. I made the exact swap as you from 3.42 to 4.10. On the street, there is much less down shifting for simple passes which I think helps gas milage, not that it matters Get em!

 

FYI...All gear ratios are stated for a 26" tire. Most trucks don't run the actual ratio they buy anyway"taller tire". In short Go big, get the 4.10's

 

I went from the 3.42's to 4.10's in my 01 rcsb and love them. With out a doubt the best money I spent.

 

my 99 came with 3.42's.. i switched to 4.10's and havent looked back.. i noticed a huge improvement as well

 

Cool, thanks for all the tips!

 

Anyone know the formula for final drive ratio with the tire dia. factored in??
I'm running 29" tall tires with 3.73's ???