I pulled the same fifth wheel with two different trucks. The first was a 2004 F-350 crewcab shortbox 4X4, 6.0 PSD. The second is a 2013 F-350 crewcab shortbox 4X4, 6.7 PSD. The 5th toyhauler has a GVWR of 13900 but I know I was closer to 15K fully loaded. The new truck just felt so much better while towing. I made emergency stops, both practice and real and the new truck could defiantly stop it better. I just felt like in the new truck I wasn't being pushed around.
Place me in the camp that your early 2000 F-350 is less than marginal at best. Any 350-3500 truck after 2013 would be another magnitude better and a dually would be another magnitude again better.
My 2013 F-350 has a 5th wheel rating of 15900 while my new toyhauler has a GVWR of 16500 so I'll be limited in loading by 600 pounds but that shouldn't be a problem.
Earlier someone suggested loading 1000 LB in the rear to reduce pin weight. It won't reduce it as much as one would think. When I load my 1100 LB RZR in the garage, it only reduces the pin weight by 100-200 lbs. Same as when I put 120 gallons (960 lb) of water in it which is located at the front of the mainframe. It doesn't increase my pin weight by 960 lbs. This must be because of the equalizers on the axles distributing the weight across the whole frame.
I just shopped for several trailers and there seemed to be a pattern of trailers that grossed at 16500 and the next step up was trailers weighing 18-19K. The general consensus (RV dealers and ford service managers) was the 16.5K trailers were targeted at SRW trucks and the 18K+ were for DRW and larger trucks.
The 6.0 PSD POS in your truck is going to be your main limiting factor. I spent $10K making my engine work right and it was finally good right up until the block broke.
