Stay away from a Ford anything with a V10 (they blow the spark plug out of the cylinder head). I would shy from a 6.0 too..unless you know every detail they did to "bulletproof" it. I had a 2005 F250 with a 6.0. And g/f had a V10 in her ride years ago. Both of them about killed me financially (or should I say the Three of them if you count her..lol..jjk). Also you can consider air bag helper suspension in the rear for extra payload. I have some on my F350. They are easy to install, not too expensive, can let air out if you not going anywhere with towable, you'll have better handling , better braking, better fuel mileage using them. This is because you can air them up and bring the truck back up to standard ride height. This is IMHO.