I don't think it would be worth the money to change from a 3.55 to 3.73 unless you could find a complete axle assembly in a salvage yard for cheap. I'd go to 4.10.

 

Why is the GVWR more important than GCWR?

My truck is rated for 6600 lbs GVWR. Figuring an estimated weight with us, a full tank, an ice chest and typical whatnots inside, along with 200 lbs of misc stuff in the bed I'm at 5700-6000 lbs.

I have a 2 WD.

So does a higher gear add more to what you can pull? Going to a 4.10 gearing shows to add 2000 lbs.

 

If you are at 6000# loaded up, that means you only have 600# left for the WD hitch and trailer tongue weight. That's going to limit you to a gross trailer weight of around 5000# or less. You will exceed the truck GVWR before you exceed the GCWR. At 5000#, a 5.4 is fine with 3.55 gears.

You can change gears all you want, but that does not let you exceed any of the truck's ratings the way the truck was delivered.

 

Changing the gears to 4.10 won't be like buying this model with them installed from the factory? Is there more to that then just the gears?

Is there a way (other than a CAT scale) to know what the truck weighed from the factory? My title claims it weighs 4700 lbs. My manual shows a GVWR of 13,000 lbs with a max trailer weight of 8,000-8,300 lbs. Using the 8,000 lb that gave a truck weight of 5000 lbs.

Quite frankly I don't see why I'd have any additional weight in the bed, and with it detracting what I can pull I'd put that in the trailer. I was told 4700 lbs was too light so I used 4800 lbs in its place. This would put my fully loaded truck weight between 5600-5800 lbs. It has a GVWR of 6600 lbs. This should leave 800-1000 lbs, but I'm looking at 100 lbs less. Tongue weight should be about 10% of the trailer, correct?

Keystone lists a hitch weight. Is this what would account for tongue weight?

I'm guessing adding a leaf spring doesn't change the rear weight handling?