My 2004 1500 4.7L 2wd feels sluggish, like something is holding it back when accelerating

[g-nut]

My 2004 1500 4.7L 2wd feels sluggish, like something is holding it back when accelerating.
In 2006 I had a 2004 1500 4.7L 2wd for a work truck. It drove very well.
About 2 years or so ago I got a smoken deal on a 2004 1500 4.7L 2wd quad cab. It needed a lot of work but it is running and driving good.

* My only issue is the one noted in the thread title. When accelerating, from nearly any speed, if feels like something is holding it back. Like I have another truck on a trailer behind me.
* I've serviced the motor. Oil changes. Recently changed timing chains. Replaced all of the vacuum lines and rubber hoses. Flushed cooling system.
* I've changed rear axle outer bearings and gear oil.
* I've replaced all the brake pads and rotors.
* Replaced 2 brake calipers.
* Replaced both front wheel hub assemblies.
* Replaced 2 O2 sensors.
* Have no check engine light.

Anyone have any thoughts, comments, suggestions?

Thank you.

 

[rzr6-4]

Miles? Could be due for plugs and air filter.

I'm not very familiar with the EGR myself but when things get sluggish I frequently see that suggested.

 

[g-nut]

Just saw this. Didn't get an email notification.

I've replaced the EGR valve.
Recently I replaced the timing chains and tensioners. While doing so I replaced the intake gaskets, valve cover gaskets, throttle body gasket, new plugs, new coils. Lots of maintenance to it.
Basically replaced all gaskets, seals, hoses, and many other components without removing the crank and pistons.

I just have this feeling it's related to the torque converter or trans. Neither of which have I done anything with.