diesel pickup

I know of several mid-90's Dodge Cummins with over 300k on them with almost no problems at all. A friend of mine had his headgasket start leaking around 330k, they pulled it in the shop and were going to overhaul it while it was apart. Pulled the head and the cross-hatch was still in the cylinders and no ridge. New headgasket and kept on driving it.

My brother's 98 12-valve pulls good and will get around 20 mpg empty if you keep it under 65mph. I think it had around 170k on it when he rolled it, still didn't use much oil (maybe a quart to 5000) so we are looking for a cab to repair it and put it back on the road.

The only real problems I've heard of with a 12-valve Cummins and 5-speed are the loss of 5th gear and the front end on the 4x4 will not take much abuse before it starts loosening up.

casey in SD

However, if you intend to PULL with it, the Cummins is ONLY choice of the two.

The 6.5's were prone to overheating, made worse by the fact they didn't have an aftercooler to keep the charge air temperature to a reasonable level during heavy towing.

The 6.5 blocks were extremely prone to cracking.

Along about '96 or '97, they put piston cooling oil nozzles in the engines, which required drilling passages that further weakened the engine block.

A new long block (with the block now cast with higher nickle content cast iron by Navistar) will easily set you back $7000.00 without labor.

So you darned sure don't want to be the owner of a 6.5 whose block decides to crack!