3.73 vs. 4.30 AXLE RATIO

Thank you "all" for the quick response.
Here are some interesting facts comparing F250 vs. F350 Single Rear Wheel
6.2L SuperCab
5th wheel towing
F-250 SRW 4x4 3.73 12,300lbs; 4.30 15,300lbs
F-350 SRW 4x4 3.73 12,200lbs; 4.30 15,200lbs
Conventional Towing - Max Loaded Trailer Weight Ratings
F-250 SRW 4x4 3.73 12,400lbs; 4.30 12,500lbs
F-350 SRW 4x4 3.73 12,300lbs; 4.30 12,500lbs
YEP, this is not a typo!

PS: I did consider diesel but could not justify the cost/benefit of both the initial cost and on going maintenance.... although I totally agree diesel is the power horse.
Cummings is awesome, however Dodge does not offer a SuperCab anymore and wanting to get and 8ft box I did not want to go overboard with the overall TV length especially if we add a boat to the team.

These are not the numbers to be looking at. You need to go to the Ford towing guide and look at the payload numbers. There you will find the difference between a 350 and a 250; and significantly between a 350 SRW and DRW. The difference in payload is substantial. Sure, towing a trailer with the same engine, rear end and transmission will give almost the exact same towing numbers but that is not what you are looking for.

As you move into a heavier fifth wheel and if you also tow a boat you are penny wise and pound foolish to not get the diesel. In fact if you plan to tow the boat behind the fifth you may well be happier with a diesel dually one ton. And the difference between a super cab and a crew cab when towing a fifth and a boat behind the fifth is insignificant. You will likely be 70 feet or longer so what is another 18 inches of truck. Get a crew with a short bed if that is an issue. Get a RAM megacab dually Cummins diesel with the Asian transmission and exhaust brake and you will be set to go and go and go and go.............You already have a RAM, just go bigger.