hey albertaramfan, where are you getting you gear work done, and how much are they telling you it will cost. I'm running 3.55's myself with 35" tires. seems like shops in Lethbridge are looking for me to put their kids through college.

 

I am running 4:56 with 36's and would be running 4:88 if they made if for my front end. When I am doing 70mph I am at 2K rpm.

It cost me $2100 for my front and rear gears and a DTT in the rear with install. And that included a 500 mile drain and fill check up.

 

33" tires with 3.92 gears = 70mph @ 2000rpm. 4.56 will add a few hundred rpm, nothing drastic and those on here who have them are quite happy with the 4.56's.

 

I have 4.56's with the stock 275/60r20 tires (supposedly 33", but I measured 32" or 32.5", I can't remember which), and I my mileage has stayed pretty much the same. I recently went on a decent road trip, and my highway mileage was about 15.5 mpg (mind you, completely stock with 3.92 gears, I got about 15.75 on the highway). RPM’s at 70 mph area about 2200-2300. I don't know how the truck is with the 3.55's, but I thought that my truck was a little slow with the 3.92's. I am happy with the 4.56's, and I don't regret them at all.

 

I'd have to disagree with your shop guy. The difference between 4.10s and 4.56s on the highway is gonna equate to be about 100 rpm at 70 mph.
Now if you are concerned about what 100 rpm is gonna do to your fuel economy, then you shouldn't be looking at gears (or bought a truck) in the first place...

 

Damn DodgeNitto, I understand 2100 might have been a fair price but that is still a lot of money.

Gears a re certainly a good mod if you are going to bigger tires. I lifted my truck and then when to the 36s with still 392s and could notice a little loss. But then the 456s balanced it back out.

 

I'm dealing with national 4wd center in south Calgary I was quoted 800 for parts (Yukon Gears) and will be installing it myself.

I'm not concerned about mpg's but I don't want to make the truck undriveable as I run trips to bc and up into northern alberta frequently. As of right now I'm thinking I'll still go with the 4.56s. I appreciate everyones input on it.