I am new to the forum and have been online searching (pondering a used F350 DRW in the near future) about towing a 5th wheel, Combined rating seems best, higher on the F 350 DRW vs example my current 3500HD 6.6 Duramax. I am not a brand loyalist, I just need to be able to tow a 20k 5th wheel toy hauler safely. What is the big difference between F350, Ram and Chevy 35000 capability for a heavy 5th wheel? My basic search shows the F 350 6.7 turbo 3;55 gear ratio will tow nearly 3500 lbs more than the other two. My 08 3500 Hd shows 16,500 max for the 5th wheel and 23,500 total GCVWR, ( I think my gear ratio is 3;73) while I have seen some F 350's show over 30K GCVWR...any input?

Thanks in advance, Kevin