Changing Gear Ratio From 3.90 to 4.56

Hi guys,
I have a Western Star Tri-Drive with a DD16 and 3.90’s. I’m thinking about changing to something lower like a 4.56 or 4.30 at the least. The truck is spec’d heavy, double frame etc but right now isn’t geared low enough for the weights the truck will be pulling (150 - 200,000 lbs). Presently the truck will go just a hair under 90 m/hr, which is definitely not needed for pulling that I do the jeeps/ wheelers etc need to be going that fast.

I’m definitely aware of the fuel issue but when you’re pulling these weights the fuel economy is out the window.

I’m just getting tired of having to cover my headlights so my truck doesn’t see the hill

I’ve seen similar trucks pulling identical loads with the 4.30’s and it is a huge improvement, yet they are still fairly long legged. I’m more interested in being able to lift off in the soft ground pulling 40 or more wheels than doing 80 miles an hour.

Has anyone made this change that can offer some good advice?

Thanks in advance.

 

I know we’re not supposed to use the D word here. Are u stock and on soft leases? I know when I’m in bull low and let out the clutch...I should be able to move...lol

 

I have thought briefly about the 2 speed tears but haven’t actually looked into it. I’m thinking I should...be nice to know what’s out there.