Dad purchased the fully loaded '96 Dodge Dakota 3.9L, 5-speed, 4X4 new from the dealer. In 2005, I purchased it from him. Now 2019 I need to make a trip north to pick up a motor. Round trip should be about 4,000 miles. What with 285,000 miles on the odometer (going for 300K), is there anything I should do special to the drivetrain before I leave to insure a safe trip? I am familiar with the old 1960's A engines (273/318) which I used to build and drag race, but I am not familiar with the Magnum V-6 motors. Wondering about the timing chain for one thing. Vehicle runs fine, just a little puff of smoke when I first start it up cold in the morning. Thank you.

 

Wouldn't hurt to do the timing chain/gears/tensioner. With that many miles on it, it's probably stretched out in a major way. Plenum also tends to be an issue on the magnum engines, less so on the six though, take a look down the throttle body, see what it looks like. Changing a selection of fluids probably wouldn't hurt either. How old is the clutch? Last time it had a tune up? ALL the maintenance should be up to date. Will it make? No idea. Your guess would be much more accurate than mine.

 

I do regular oil changes, the clutch and tires are new, and it has had a water pump or two along the way. Crankshaft sensor broke a short time ago, it's been replaced also.

 

If it has has had regular maintenance and it seems fine it will probably be fine. Grease all the drive train parts in the front end. Look for signs of wear that indicate replacement is due. Maybe go with new wires, plugs, cap and rotor.
That said if you are going to climb serious mountains it may strain it. You might find yourself climbing in a low gear.