You should have no problem using the Convert-A-Ball Gooseneck Coupler Adapter, # CAB-C5G, on a 1,200 mile trip as long as the gross weight of your trailer remains under 20,000 lbs and the pin weight is under 4,000 lbs. We had one customer comment that he has been using his adapter for over 20,000 miles and it is still working great.
The only note I would add to this adapter is that there will be a noticeable difference in the ride quality if you are used to towing with a fifth wheel hitch.... view full answer...
The Reese Above-Bed Gooseneck Trailer Hitch - 25,000 lbs, # RP58079, has a 2-5/16 inch hitch ball that is held in place with a snap ring. This design allows the hitch ball to rotate reducing binding with the gooseneck coupler. It has a nice powder coat finish to resist corrosion and the hitch ball is a durable, heat treated ball.
If you are looking for a welded option, you may be interested in the Curt 25K Gooseneck Plate for Fifth Wheel Rail item # 16055, or the Curt Spyder Gooseneck... view full answer...
The Curt Spyder Gooseneck Trailer Hitch for Fifth Wheel Rails # 16085 has been tested to J684 standards according to my contact at Curt. view full answer...
The Curt # 16085 Spyder is manufactured overseas in China. If you're looking for something made here in the USA, I'd recommend the # DM5996 from Demco.
If you click the provided link, you can see a product description video for the hitch. view full answer...
The 30866 you referenced is no longer available but the # RP30047 is and would be a great solution. It can easily be used with a Reese Revolution pin box.
The correct rail adapter you'd need for this hitch to install in your 2018 Ram 2500 with the factory rail kit is the part # RP30154. view full answer...