All pickup truck diesel engines, IMHO, are grossly derated to keep the drivetrain intact. The obvious solution (to my mind) is to either buy the correct truck for heavy use (one ton dual rear end with split axle ratio) or keep your foot out of it while towing. The standard drivetrain just isn't up to snuff. True for ALL 3/4 ton and ligher trucks, none will hold up. The "big" Cummins is rated at something like 600 hp and 1400 ft/lbs torque in large truck applications, for instance. Easy to get more power, but then something will break, including the truck frame since the truck is built for light use.

As for engines, the consensus around here is that Cummins is much more desireable than the others, with the Ford Powerstrokes #2 (unless you are a die-hard Chevy fan, in which case I suppose you just eat the IPs regularly). All of them have peculiarities, but long term the Cummins seems to run forever with the least trouble. The older Internationals Dodge used do too, but I don't know if the new ones are the same.

For normal use (no towing greater than GVW), any will work. For heavy towing (greater than 5000 lbs trailer weigth), get a tougher truck.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!