Those trucks are only making 40 or 50hp more than what I suggested to be the max for a 7.3 vintage superduty, yet they have coolers on top of coolers on top of coolers. Hell, the diffs come with finned cooling cover plates. Fuel coolers, big trans coolers, hell they don't even offer the ZF6 anymore because..... yep.... it couldn't hang....
I'm sure that loaded to around 30,000lbs and running down the interstate for a few hours the driveline on those is getting a little upset even still.
I'd be interested to see what they are really making. I'll tell you one thing, they have a lot more gear. But power isn't what people think. If someone says a 12 dmax with 400hp is the bees knees, I feel for them. Granted most diesels wind up tuned with airflow enhancements which might make a huge difference, but my brand new truck is running stone stock and its not 300 hp towing. Not even close. Unless you murder the pedal it's not.much different than a tuned 7.3 in capability. What I've learned quickly since running 175/100s and a 38with custom tunes is the truck(my 7.3) will pull much easier, harder than stock but it's getting hot faster everywhere. Not to sound retarded but my truck stock with gauges and 100 hp banks chip, you know a one trick tune, pulled up to the point where it wouldn't hurt anything but pulled just a little harder than stock. I'd say t was really about 60hp.
The 7.3 in any form will outperform most others if you need to back something.heavy with control. The other day, I backed a dump trailer with 10k lbs of sand in it over a curb and up a driveway. It very easily shoved the load over the curb and continued pushing said load up the drive controlled. No mashing the pedal and then letting off and then hitting the brakes. My main bitch with the dmax? The low-end grunt isn't there. It requires judicious application of throttle to initiate movement. 4lo to pull 12k lbs of trailer up steep.driveways gets old quick.
I'm sorry, I'm blathering. The old dinosaur tows like nobodies business though.