3.42s would be fine with the CTD, but you're pushing the limit of SRW. The max GVWR on that trailer is slightly heavier than the tow rating on a SRW Ram. It would work if you didn't load up to max but close, imo. I think the new Super Duty has a higher tow rating with the Powerstroke so you might check that out if you can live with the CP4 injection pump. Or check out the new Dmax - I'm not sure what the ratings are on them, but they finally went away from the CP4.
I understand not wanting DRW. I'll never own one unless it's a dedicated tow vehicle - they're worse at literally everything other than towing/hauling compared to SRW.