Go with the 4.56 then. With the 33's, it will make around town driving easier on the truck, and towing as well. You will suffer a bit on the freeway, but, in the over all scheme of things, you will still come out ahead. AND, if you want to go to 35's in the future, you will already be geared reasonably for them. It's an expensive job, do it once, do it right, don't worry about it again.

 

Ok thanks, i have the ability to change these gears myself so ill be saving a lil bit of money, is all i need is the rack an pinion gears correct? my bearing should be fine i change the rear end fluid normally 2x a yr

 

If you are going to re-use your bearing's (which is fine), all you need is a minor install kit for both diff's. Good luck. Oh yea it's ring gear and pinion gear not rack and pinion.

 

Yah i knew that haha oops

 

Since we're on the subject, how much rpm bump at 60mph if I switch from 3.55 to 3.70 or 3.92 running stock tires? I don't want bigger tires, tow only 3000lbs a few times a year, lots of freeway driving.
Truck runs between 1500 rpm to 1750 at 60mph, that's too low, like it to be little higher rpm on freeway. Currently has to downshift out of OD on mild hills at 60mph, understandable when rpm only 1750, that's not in the optimal rpm power band.
And what are the different options for correcting the speedo? I have SCT so electronic correction isn't an option.

EDIT: Found the the answer to the speedo adjustment question.
https://dodgeforum.com/forum/2nd-gen...edo-reset.html

Speedo change not affected by gear ratio change in 98 and newer trucks. Tire diameter change however does require parameters to be changed using a DRBIII tool, or dealership can do this.

 

Going from 3.55 to 4.10 would bump you about 240 RPM at 60, in O/D. Lower numerical ratio would give you less of a bump.

 

Thanks, HeyYou. Think 4.10s would be perfect, put me between 1740 to 1990 rpm on freeway. That way when I'm driving 65mph I'll be close to 2200 to 2500 rpm, right in the power zone.

EDIT: Think this rpm bump from 3.55 to 4.10 would be closer to 400rpm increase, might go with 3.92 gears, that would be about 250 increase.

 

Quick question on this topic, but are 4.10's or 4.56's better for 305/75/16=34's pretty much. Because when I do my lift I'm thinking between 285's, 295's, or 305's and just wanted to know what gear would be better for all those tires. I myself think 4.10's will suffice since I'm not wanting to go over 35's( I know the 305's are really close tho) I rarely tow or haul anything with my truck, maybe in the future a atv or some random stuff here and there but that's it.

 

Unless you already have 4.10s from factory, you might as well just put 4.56s in there since its already going to be torn apart anyway. Shoot I think it's pretty much the same cost for the gear sets...you won't regret going to the 4.56s. Buttttt if you already have 4.10s and don't do any regular hauling or towing, then you should be ok to go to 305 tires without it hurting the drivetrain, assuming everything is functioning properly

 

No I have factory 3.55's that's what I was wondering on. I'm just concerned if I do 4.10's and then actually do some hauling or towing that it might hurt stuff but when I do a manual trans. swap would the 4.10's still be ok then?