The newer International DT-466 engines seem respectable. Wet sleeve (rebuildable) 7.6 liter/466 cu. in. engines which seem similar to the Cat C7. Designed for MDTs and have horsepower ratings from 210 to 300 and up to 860 ft/lbs of torque. I agree about the older one though...probably is pretty slow with the 5 speed to boot.
Full specifications on the DT-466 if anyone is interested.