Just do what everyone else around here does. Get a front and rear bumper, rack, tires, sliders, skids, hi-lift, suspension lift, winch and carry around enough gear/tools to service an oil rig and it'll slow down just fine.
Exactly, except your missing a few key elements. This is such an easy one...
First Slap in two of the heaviest batteries you can find because you never know how many batteries you will need. Plus fill up the entire engine bay with compressors and switch panels for lighting...
Next do the rear bumper. Put a huge steel structure (2-300lbs) on the outside of your steel bumper because two bumpers are better than one.. obviously. Now, cantilever out a big heavy tire carrier plus some fuel cans or whatever... and throw on a ladder for good measure.
Obviously slap on the mandatory sliders, front bumper, winch... Just do it all steel since steel is heavier and we all know heavier is better.
Now for the inside. Put in a 200lb drawer system so you can carry around a kitchen, plus all types of neatly organized tools and gizmos. Oh almost forgot must have the fridge and the contraption to hold that and lower it... That should add another 400lbs or so. Might as well keep that fridge on all the time with stuff to eat... so better do a solar system.
Now for the roof, must have the RTT and all that jazz to create some wind resistance or maybe a 1.5k trailer to lug around more stuff. Maybe both.. because more stuff is always better and 100% required to camp for the weekend...
You should be slowed down plenty at this point and be over the rated GVWR and be close to single digit MPG. But for good measure, throw on some bigger E rated tires . The bigger and heavier the better (37s if you can cut enough) Might as well do beadlocks too as they can double the weight of a wheel. Shit I know guys that fill their tires with water for better center of gravity, so do that too.
Gearing needs to be consider also. Drop it down to a 3.05 ratio. This will help keep the RPMs and TQ down and keep the torque converter from ever locking up.
You should be well bogged down now and less over powered.
Final step will be the sprint suppressor. This will sit between the pedal and the ECU and modify the signal so that when you input 50% throttle, the ECU will only see 10%... It's what the 5th gen should have come with from the factory as these things are just way to touchy from the factory.
Should be a real Joy to drive at this point.