A lot of good information here. I have a '99 F-250 with a 7.3 diesel and 4R100 tranny. Mine is a supercab shortbed. I pull a 20' gooseneck trailer every other day with it hauling anything from a load of square bales to a tractor and disc mower to a load of steel. I have had absolutely no problems at all. You can definatly tell it's a heavy load but nothing really bad. Stopping is no problem at all. The truck actually stops better with the loaded down gooseneck than it does without any trailer at all. And that's with just one brake axle on the trailer. As far as turning clearance there are no issues at all. I can turn the trailer just as sharp in my shortbed as my dad can in his longbed. Now if it was a 5th wheel I would have issues, but they make sliding hitches for that as well. My truck being as short as it is also offers better weight distribution. As far as hitches go, a B&W turnover ball is one of the best, but it's not a necessity. Newer 5th wheel hitches offer the same flexibility as gooseneck hitches, however it won't really matter in your case since you're pulling a gooseneck. I agree with the need for a deeper transmission pan, a bigger cooler, and a temp guage. They are a dime a dozen compared to the cost of a trans rebuild. The best thing you can do is to try to keep that torque converter locked up as much as possible. So really, there's no reason why you can't pull the load you're talking about. (except for the cost issues) Also, my truck just hit 238,000 miles, most of which was spent pulling a trailer of some sort. Just take care of the truck and pay attention to what it's telling you and you'll be fine.