I have never posted a thing in my life so this is a total first. Looking at a 2004 f350 lariat drw 6.0 diesel w 169k miles. The mechanic who maintains it says it's been meticulously maintained and bulletproofed. Single owner. This will be a tow vehicle for a a fifth wheel (yet to be purchased). What should I look for? Never owned a superduty

 

I bought a '01 with 243000 miles on it, but it's a 7.3L. I avoided 6.0's like the plague. However I always heard about "bullet proofing" them. From my understanding there are different grades of bullet proofing and you also have to take into account the skills of the bullet proofer

 

As a long time 6.0 owner now at 156k I can say if the mechanic is telling the truth (you'll have to be the judge of that) you should have no worries.
If it has been studded, the EGR deleted or "bulletproofed" as the mechanic claims and the oil cooler is good (search in the 6.0 forum for oil cooler to find out what you need to know) you should have no issues.
Just bear in mind that it will require 4 gallons of synthetic oil and a filter every 5k miles. DO NOT cheap out on the oil. Seriously. Very important on that.
Also fuel filters (both) every 15k.
Mine has been very reliable except for the damage I did to it.
In 156k miles it's had;
STC fitting. A known failure point on 05-06 6.0 trucks.
Head studs. Due to me playing with tunes.
Left rear brake caliper.
Alternator.
Everything else is maintenance stuff.


Whatever you decide good luck.

 

Welcome to FTE and Internet Forums!!!!

Can't speak with any authority to the drivelines of that vintage, but you would need to know what kind of life it led... If it was used for towing all that 169k, it may well be on its way to worn out. At the very least, you may be in for front end suspesion components, wheel bearings, etc..
People generally don't just sell a high mileage rig because it's perfect.. Your job is to figure out what closet has the skeleton...

 

That's not many miles for a diesel but you really need more specifics on what "bulletproofed" means. HPOP, oil cooler, egr cooler, studs, etc.

Regular maintenance isn't bullet proofing this guy. Get a history of work done.

 

I bought my 05' with 168k I did have to replace the oil cooler and deal with the egr. At this point unless it has been done you will be needing ball joints, tie rod ends wheel bearings. Plan about 2k for it. Other than I just had a trans line blow out it has been a daily driver and now has 176k on it.

 

This is some of the best reading the 6.0L Forum (aka Mark) has put together on buying a used 6.0:
https://www.ford-trucks.com/forums/9...used-6-0l.html

More info:
https://www.ford-trucks.com/forums/1...eral-info.html
Ford Truck Enthusiasts Forums - View Single Post - Just bought 06 F350 FX4 6.0!!

Read it, digest it, decide if the work that it'll probably take is worth it for you. Honestly, if you're looking at any truck with 170k on it you can't be afraid of wrenches no matter what the make/model/engine is. Any used vehicle is a gamble, the 6.0 isn't any more likely to be trashed by that point than any other powertrain out there.

A single private owner is a good sign, maybe he just wanted to upgrade to a 6.7 after a good decade with his last truck.