New used truck

Maintenance records available?

Ride quality is greatly affected by any optional payload packages.

King Ranch has extra insulation for quietness.

Well older gas to newer diesel should be about the same sound level.
Ride the 2004 likely had a GVWR of about 11,000# to 11,500#, the 2017 has a 14,000# GVWR.
Please check your rear tire pressure the unloaded rear tires can be run as low as 35 psi , full load will be 65 psi. I know the sidewall states max pressure 80 psi, but the four tires only need 65 psi to carry the max axle rating.

It's a dually with 14k GVWR.. Running empty, of course it's gonna ride a bit "rough" (probably not as rough as my dads 71 F250.. That thing will knock the fillings out of your mouth!)... Put a load on it and compare to your 04 and report back.. ha, ha.. Compared to the rest of the vehicles in your garage, I'd say you are pretty used to a 'cushy' ride?? :)

Good luck!

Mitch

Half of my miles have been unloaded in my '19 F350 dually and I never complain... no it's not my 2500 but still very compliant considering... I wonder what PSI the rears were at?

Can you tell how much of the perceived roughness was from the rear vs the front? The dually has two more tires(with steel rims) and a heavier axle so a lot more unsprung weight. That adds to the roughness plus it probably has stiffer springs and shocks to handle more payload even before any payload packages are included. The added noise surprises me.

E-rated tires and over inflated tires in the rear with no load will make all HD trucks ride like a hay wagon.

My truck in sig rides a tad rough when empty, but I expected that being a DRW. Even w/ 1k tube sand directly over axle (in an attempt to aid it in snow), she's still a tad rough. Added an add'l 300# tube sane behind axle and ride improved but didn't help much in snow-----oh well.

Now w/ the RV attached and 3700 pin, she rides very well. Downside is the rear suspension will BANG on downstroke after encountering a expansion joint, or pavement seam. I removed the aux spring helper brackets and that helped a lot, but still does it. W/O anything to compare it to, I figure it's just due to it being a DRW and designed to carry heavy loads thus a stiff suspension.

Noise wise, It's on par w/ the '15 6.7, but by far quieter than my '03 6.Uh-Oh which I aptly had by the diesel plates on doors:"Daddy Likes The Rattle".

Lol, and it's about twice the truck an 04 is for capability.
Quieter? Seems suspect even though you're comparing to a gasser.
Rides rough? What do you want out of a truck with a 5k payload that can tow 30k?
And the springs are probably mushy in the old truck for comparison.

Heck, I'd just keep the 04, sounds like a better truck by your description.