I know not everyone is a fan and most folks are not convinced it can work but I thought I'd pass along my set up with an Anderson 3200 hitch (steel not aluminum).
I have a 2019 CC 2500 with RAMboxes. Can't get 5th wheel prep or gooseneck prep in a RAMBox truck so I installed the OEM puck system (82215838AB) myself. This let me use a Reese Rail Kit (30154) to mount the Anderson 3200 in. The combination is much lighter than a typical 5th wheel hitch and breaks down quickly and separately for easy removal/installation. I also installed a Curt 5th wheel 7 pin connector (C56070) in the bed, got to be careful with the location with a RAMBox bed but it looks OE and works great. The 3200 is rated for 4200 lb pin weight and 20,000 lb trailer weight (depending on your trailer, this may not be enough load capacity). My trailer's frame is a Lippert 1620 with a RotaFlex pinbox. This pin box is very level to ground. Other pin boxes that extend downward would likely work even better than my setup.
There are some specific things that help this work for my rig that might not work for others:
* The Andersen cup is mounted on the pin to give maximum cab clearance (cup to rear of pin)
* The cup position also improves the gap between the rear of the pinbox and the bed rails of the RAMBox bed, which is the main consideration in this scenario.
* My 5th wheel is a Cougar 30RLS, half-ton series. Cougars typically have trimmed lower front-cap corners that help clear the cab
* I started out with the Andersen ball in the highest position to ensure maximum bed rail clearance on deep turns. This yields about 9" from bedrail to under side of the 5th wheel overhang.
* My truck has Auto-Level Air suspension so I can lower it 1" to keep the front of the 5th wheel more level. In the low setting, the 5th wheel is 3" nose high, which is still acceptable, though more level is preferred to keep pressure off the rear axle
* The Reese Rail sits higher off of the bed than typical, more flat, rails. This extra .75 inch or so helps with the bedrail clearance of the pinbox but does raise the trailer nose. I guess it could cause the pin box to need to be raised in some cases to keep the trailer more level.
* Since the original set up of the hitch, I measured and found that I was able to lower the pin box 1 position (has the effect of raising the front of the trailer) and lowered the Andersen ball 1 notch. The reason for this is to allow the Ball stem to sit more deeply in the hitch frame and not be in the highest (3rd) position, for my peace of mind. Net effect on camper level is the same and bedrail to underside of overhang distance stays the same.
This set up allows for a near 90 degree turn (deeper than I like to see the trailer axles rack) and actually comes closer to the cab than the bed rails. I really enjoy the ease of operation and how solid the setup and connection feels. Very smooth, very quiet. I've attached some pictures for reference.
I used some YouTube videos for reference when I was researching this before we bought the 5th wheel. The example I found didn't use the pucks, just a typical rail setup. I'm certainly not the only one to have this kind of thing work for them but it may not work for all scenarios.
Hope this info is of some help. I spent hours/days/nights research/fretting/praying over whether this setup would work or not but so far it has been exactly what we needed. I have 2022 3500 CC Limited with RAMBoxes on order so I will be using this same setup for it too.
