In college I used to drive/maintain a fleet of 1/2, 3/4 & 1 ton trucks for construction /utility companies... When regularly operated near payload capacity or for serious towing the gas 1/2 ton trucks did not hold up well requiring constant brake, tranny, and suspension work... Diesel work on our 1 tons was very pricey making the gas 3/4 tons the best bang/buck.
IMO the OP could trade-in his Titan for a used 3/4 ton gasser and almost break-even on price. In 2013 I bought a 2011 Ram 2500 CC w/5.7 Hemi, 3000 lb. payload & balance of powertrain warranty for $14,000. The 5.7 Hemi has 385hp compared to the Titan 5.6's 305hp plus the 2500 has a beefier frame, suspension, and brakes.
Our entry-level Ram 2500 CC has a payload of 3,000 but a GCVW of only 15,000 which is actually LESS than the Titan... IMO Ram went light on the specs to not compete with their diesel sales whereas Nissan went bold on specs to compete w/other 1/2 ton manufacturers... So even with similar specs there is a big difference in towing experience & safety.
Our TT is 8,000 loaded so loaded with all of our gear we operate very near our GCVW, although we are 500 under our max payload of 3,000... We have no issues towing throughout the Smoky Mts., in high winds, and on bad surfaces. In comparison, the OP wants to tow a TT that is already 8,000 EMPTY which takes his Titan well-over Nissan's already liberal payload & GCVW specs...
IMO you can get-away with overloading for a while but eventually something breaks, you can't stop/control in an emergency, etc. and then you have to live with the regret of your poor choices. So IMO the OP needs to find a safer choice for towing a TT that is 8,000 empty with GCVW over 15,000... IMO he can sell the Nissan & buy a 2500 for less (net) than the parts would cost to upgrade his Nissan... Yes, technically one could "lose the house" if your overloaded condition caused serious injury/death but IMO the "ambulance chasing" lawyers are targeting commercial trucks w/huge insurance limits...
2011 RAM 2500 ST Crew Cab 5.7 Hemi
2011 Primetime 3150BHD Touring Edition
Days camped in 2016-36
Days camped in 2015-37
; Days camped in 2014-31