Ram 3500 (6.4 Hemi)3.73 vs 4.10 with TC

I have a '14 3500 with the 6.4L 3.73 gears, get 9mpg if I am lucky hauling around the 4k lance 861. Plenty get up and go at a cost to MPG

My Super Duty came with 373 then I upped the tires to 35" reducing the gear ratio to about 330. It was hating life on the mtn passes wanting to go to 2nd gear and scream at 5500 rpm. Also lost 2 mpg. Changed them out to 430s which with the tires put it right about 410. What a difference!! Went back to pulling the same grades in 3rd at 4500. And got my 2 mpg back!! 373 may work fine for a light TC but the day may come when you want to add an enclosed utility or boat.

My f250 460 gasser with the 4:10 gears and the E40D trans is a winning combo... I get 10-12 loaded with my 4K lbs camper. I would not even consider any lesser gear ratio.
When towing my Zuke, Baja or our 3Klb trailer with a 700lb motorcycle in it climbing a 17% grade makes that 460 work about as hard as it can to keep up!

I do have 19.5's and see a speedo difference of <>4mph at 60. So that makes my effective gear ratio about 3.9...

Jim

While you're ordering the 4.10, order the limited slip differential too (or the electric locking differential, if it is available).

Just a thought, if you went with 4.10's and were unhappy, when it comes time for tires you could go to a larger tire to change the overall ratio. Obviously you could do the same with the 3.73's and run smaller tires, but most people don't want to run smaller tires.

What transmission does the truck have?

With a 6 speed I doubt it will make much differace when camper is on board.

I went through this same debate (same truck, also a lightweight camper) and ended up ordering the 4.10. I still can't say if it was the correct decision but I do now have some data. Driving 65 MPH on flat highway I am at 1500 RPM. On an incline it might downshift and go up to 2500 RPMs. This is low RPM. I suppose that the RPMs would be lower with 3.73 axle ratio. But with 3.73 I understand that it would downshift to lower gears sooner then with 4.10. So I am still a little confused about the tradeoff. I can say that with the 4.10 that it would only downshift when I needed to pick up speed on an incline. On flat road it would be nice steady 1500 RPM.

Driving in the Appalachian Mountains I needed to push the RPMs much higher to maintain speed. I had enough power but not it seemed excessive extra power, so I suppose the 4.10 was good to have.

I think you can get a better deal by custom ordering anyway. Trucks on dealer lots were the more expensive trim packages. I started with the lowest cost Tradesman trim than added options like power door locks, which depending on what you want can end up less expensive then starting from a higher trim. I decided on the exact options I wanted then shopped around dealers until I got the price I wanted. I think it was less than 2 months and my new truck arrived. It was worth the wait for the cost savings of ordering only what I wanted and to get the exact options I wanted (like 4.10 axle ratio).

Overhead cam V8's like to spin and make power up top. You'll be happier geared down at a mileage penalty...The Ford guys that get the 6.2 gasser....love the 4.30 gears when pulling weight.


With a TC...you will have the aerodynamics of a wall...it's not so much the weight, but resistance your up against.

A truck camper won't put enough weight on the truck to need a lower axle ratio, so either ratio will do fine.

Even so, if it were me, I would get the 4.10. Most pickups are geared too high with the standard gears. I always go for the lowest ratio possible. Low ratios have high numbers.

I agree about the long bed being the better choice for hauling a truck camper.

Rear axle ratio shouldn't effect payload at all. Any modern truck has more than enough power to move it's own GVWR. It's the towed weight that really makes the axle ratio come into play.
I'd pass on that truck for a TC simply because it's a short bed. That will significantly limit your choice of campers and finding a used one will be even more difficult.
I think either gear ratio will do the job but I'd want the 4:10. If you load the truck to capacity and drive up a mountain you'll be glad you have it.