I have a 2002 F-350 SRW with the V-10 and a 4.30 axle. We recently sold our Citation cabover and bought a fifth wheel, but we hauled that 3200lb camper with a trailer full of atv's all over the western U.S. with no trouble. I have owned the truck since new, and I can tell you it will suck some gas. Unloaded the best I have ever seen is 12.5 mpg, and I average 10.5 empty. Driving in mountainous terrain with camper and trailer in tow, I have seen as low as 6 mpg. Power is adequate on ours and I understand the newer ones are even more powerful. My only problem in 90000 miles is that recently it has begun to consume more oil. Nearly 2 quarts in 3000 miles. Ford says it's within spec, and it doesn't smoke. Despite this, I will probably trade it in a new one (V-10 again) soon. You might check out www.fordtrucks.com
too. They have some good info on these trucks.