PAYLOAD...that is the rating you need.
5th wheel pin wet is 'carried' by tow vehicle
So you need to look at your certificate sticker on door post and see what is listed as payload (yellow sticker with tire data)
That payload is max that truck has available.....then you have to subtract ALL weight of passengers, any stuff inside truck, the weight of a 5th wheel hitch from that payload number.
Amount left over is what you have to carry the pin weight
Pin wet is typically 20% of 5th wheels weight, BUT don't go my dry weight/unladen weight numbers. Use the 5vrs GVWR and 20% of that figure
17,400# GVWR 5vr...20% ====3480#
That is what you would need in available payload (after all other weights subtracted) to carry the pin weight of that trailer.
Probably 10,000# GVWR
RAWR probably 6200#
Total payload before subtractions probably 3000# or less depending on trucks trim level
Most likely a 12,000 GVWR 5th wheel will be heaviest (2400# pin weight) IF you use stay within trucks ratings (GVWR, Axle Ratings, Tire Max Load Ratings, Payload etc)
So one either using the ratings or justifies being over.
Example of sticker showing 2812# payload (cargo capacity)