Towing is a concern, looking at the specs, with a 3.73 rearend the 6.0 is rated in the 9,000lb range. Most fifth wheels start in the 8,000+ range and up empty with nothing in them. So you would have to opt for the 4.10 rearend which would get worse mileage to get the higher towing capacity. Looks like people are getting 7-9lbs towing and up to 15-16mpg best hwy with no towing, not great.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85