I am sure I am not the only one to think of this, but who has done it, and what's the cost. My truck has the 4:10, limited slip rear end. I would like to keep the limited slip, but change the gear ratio to 3:73. I do some towing, but not enough to justify the 4:10's. My 01 had the 3:55's, and that was good for the amount of traveling we do. I figured the 3:73's would be a good comprimise between power and fuel economy, as I travel 80 miles a day, 4 days a week, for work. Plus, if we go anywhere as a family, we go in the truck. I would even be willing to do a swap with someone in Florida, if they wanted the 4:10's. Thanks in advance, Baron.

 

What size tires are you running? I went from the 4.10 ratio to close to 3.73 by changing tire size. My truck is set for towing and had no issues even though it is a 6.7 and yours is a 5.9. The H&S corrected the speedo to account for the tire size change. I used one of the online tire ratio tools to determine the right tire. No difference in handling either.from the tire change. It also put the RPMs into the sweet spot at 70 when not towing. It also gives me a reason if they ever smog test and check for a tuner as I will claim I used it for tire correction
Brian

 

I've thought about changing the tire size, as I did on my 01, but can't get answers. Having the dually, how tall can I go? Can the speedo on the 03, be calibrated by changing the ABS 'ping rate' like I did in my 01? Currently, I am running 235/80/17's.

On my 01, I went from the 265/75/16 to 315/75/16's and had the ping rate change to 601 ( if memory serves me correctly). The only thing I had to do was 1/4 spacer on front wheels, to get it away from the frame at hard steer.

 

I would love to trade with you. I do a lot of heavy towing. But I live in Arkansas just a little to far.

blacksmoke

 

Yeah, maybe just a little to far.

 

Yea. I'm in Tx. and when I read this my first though would be a swap. That's a long way off though. I wouldn't mind having a 4:10 every now and then.

 

I think you can go about as tall as you want with tires.... How about a nice set of 19.5" wheels and HD tires?

I did a swap once on a Ford I had. Went from 3.55 to 4.11. Total cost was only around $500 including parts and labor. Making sure you have a good shop that knows how to properly lash the gears is imperative.

 

I think the best thing to do is hold out till someone comes along close enough then park the trucks side by side and make the swap. Depending on the trailer your pulling, you might not be able to go with green giant looking tires.