i have a 06 dodge big horn edition which came with 20 and 3.92 gears i cruise at 70 mpph @ 2000 r 4.56 to much or 4.10 better. keep in mind i have 33 inch tire and have no plans to change them with the cst 4 inch lift just want a liitle more power since i am pushing more air under the truck and over the truck

 

Are you asking which gears would be better?

If so, the 4.10s will make an improvement, but 4.56s will be much more noticible by far.

But for daily driving, I would probably stick with 4.10s since higher gears put unneeded wear and tear on the engine.

Are you doing this yourself or having a mechanic do it?

 

My PW turns 2500rpm@75mph. It rarely goes back to 4th on the freeway unless I'm towing. Real happy with it, real easy to tow. Also, since break in and going to synthetic oil, I am getting 13-14 mpg, as compared to 11.7 (best) before the switch, not bad for a 6500+ # truck that is 6 1/2 feet in the air.

Also, 3.92 to 4.1 is less than a 5% change, you won't be impressed if you are unhappy with the current gears. 16% for 4.56 gears will increase to about 2300rpm@70mph, not a huge diff IMO.

 

Honestly I would look at 5:13's. DO a search and get the formula for the rpm range.

Installing gears won't make your engine wear out sooner. trying to overwork it to turn those big, heavy wheels will though. I love my 4:56's and should have done it a year ago. I run the 17's though.