I'm helping a relative look for a new F250. I know gas Chevys but he insisted on diesel F250. Thanks for any advice on specs.
1. We see there's a high performance engine option but not sure if that's needed for ranch type towing of hay/ cattle trailers. Probably never over 16,000 pounds or more than 100 miles. Will not be towing a camper but will do some long highway trips.
2. 95 percent of the use will be highway but he wants the truck to tow with occasionally also so wondering which rear end gear ratio would be best with the diesel engine.
Any other option suggestions or spec advice? Planning on the king ranch package and a Ford extended warranty.

Definitely the High Output 6.7 is worth every penny. Also you want the 3.73. I have a Tremor but the King Ranch is great option

I have a 250 with the High Output and 3.31's. With the 10 Speed you have plenty of gears for towing, and it gets over 20mpg on the highway cruising at 80mph. The high output is definitely worth it, when you're spending that much money on a super duty, what's another $2,500 for a much more fun truck to drive...

3.73 is not available for diesel. That's a gas motor pairing and it's the only option. Diesel gets 3.31or 3.55. Both gas and diesel can be had with electronic locking differentials.

Double check this with the order guide.

He doesn't need a diesel for his use but it does make towing nicer.

King ranch is the only trim level that allows two tone paint so make sure he knows that in case he wants it but he'll lose front bench seats. I think losing either is a crime but that's the world we live in.

I had to look at mine it's 3.55

Another vote for HO with 3.31. I pull a 35ft 5th wheel travel trailer and it handles it fine. I also love my King Ranch interior.

King Ranch and 3.31 rear end
I have a 21 and the best truck I have owned. Use it as daily driver (100 miles a day)with 164k on it. And pull 33ft gooseneck from time to time with no issues.
Better after warranty is over if you know what I mean!

In my humble opinion an extra 25 hp and 125 lb/ft of torque is not worth $2500 for the high output. But it's not mine and if that's what you want well by god this is America!