All of this is accurate until the end.
NO COVERS WILL WORK FINE FOR HIM.
He needs to completely remove his rails and purchase new rails.
The ONLY COVER that will work for him with black rails is the Mopar SOFT Tri-fold cover.
This is the part number for it 82215862
I got a spare one if you want it in MA xD
This is a copy and paste from store.mopar.com
Description: Utility rails that run across the fore-aft direction in the bed. These rails only are applicable to the soft trifold tonneau cover offered through the factory on 5'7 bed with Rambox. Replaces: 82215810.
These are the "silver rails" that are so important that Ram decided to not provide them to you when you bought your tuck.
68027049AD
68027048AD
Another interesting thing is there are install instructions for the black rails but not the silver rails, so I have no idea what is used to get a "factory seal" it also doesn't come with screw so you need to re-use your existing screws in your black rails. Specs on the black rails report 7.7 ft lb torque.
This is one of my threads if you want to see pictures of the abomination that Ram provided us poor Rambox guys
Title says it all. Went to install a Gatorax retractable bed cover today and it's not possible to mount it on my truck. The instructions for a 2019 ram with ramboxes doesn't match my truck and upon looking myself I don't hlknow how ANY Cover can fit except the soft one it came with. Anyone...
5thgenrams.com
I'm currently pissing in water on both sides behind the rails as Ram doesn't provide any kind of seal and the black rails have a seal built in. The weatherstipping I got just isn't up to snuff and it takes me around an 2 hours with 2 people to take my cover off and change the weatherstipping (and then keep the truck dry for a few days so it has time to set).
I'm 1000% not salty about buying a $80k truck and needing to spend $400 on rails to be allowed to use a secure cover on it.
If you don't need security get the Mopar soft tri-fold. It's actually a really good cover and comes right off in under 30 seconds if you need full bed access. Unfortunately I can't use a soft cover due to having snowstorms up here and carry equipment that dwarfs the price of my truck that would be very bad if was stolen by some hoodlum with a box cutter.