Guess I'll add my comments.
Going from 11.7K pounds to 14K+ is not lightly loaded in my opinion. That's 2300lbs+. If you are carrying that much extra weight you are a hoarder!
Not sure how the discussion became a 3/4 ton topic? The OP stated he is looking at 350/3500 Ford/GM.
And then again the Ram option has come up again. Don't think the OP is living under a rock. I'm sure he is aware Ram makes 3500 series trucks but has decided he doesn't want to consider one.
My gawd, would someone considering a new truck would you PLEASE consider a Ram and we can all get along?:) This is the third post of people considering new trucks and not looking at Ram! Maybe the next one will be.
And of course the diesel discussion is brought up. The OP is only pulling 1500 miles a year and stated he's had a diesel and does not want one. If anyone wants to anty up the add'l $10,000 for one I'm sure he'll take it.
From a spec perspective, the Ford is a better choice with 4:30 gears and the trailer is well within the specs.
S