I also tow a 10,000+ fiver and also a 24' stock trailer and I have 164,000 miles and so far no melted pistons.And yes I pull in mountains.10-12 mpg towing and 18-20 empty depending how I drive it.

 

Seen lots of 4.5-05 with piston damage. Its hard to say when or why it happens. Do some searches on comp diesel forum or on this forum. Some think its from the 3rd injection cycle used to scavenge the cylinder better for emissions.

The 07-08 CTD 6.7 RE68, are great truck, once you get off all that emission junk. I've pulled some killer hills hauling my 5vr, you lift the hood and see the turbine housing/exhaust red, but the motor is still going strong. Pulled tons of hills with the pyro over 1500 deg's. Besides the cab issue of the 2nd gens, the older motors seem to take so much more abuse. I'm still running the original motor, so far. Once this motor goes, I throw in a 12v and get my 1 millions out of this truck, so I can get my original purchase value out of it. I've owned this truck since brand new and its been modded/chipped/fueled/ and twin turboed, a few blown 8 head gaskets. A head gasket is $140 and 2hrs of work to fix. No wires under the hood and you can work on the truck pretty easily with just simple hand tools.

 

I sure love my 03 3500 HO six speed dually with 4.10. I pull 16,000 fiver with it. It has been in some very interesting places and never hickuped.

Bob

 

I have an '03 250hp... with 3.73s it was a little short on power but for $500 a Smarty Jr bumps it up to the same level as the 305/555s. Stock is has no cat and no third injection event for lower EGTs and better mileage. Just make sure if it is an auto you have the 48Re. Some of the early 250HP trucks still had the 47 series tranny.