Hi - how is the engine? We just purchased a 2006 e450 6.0 then read a lot of bad reviews. Hoping yours is doing well!
the 6.0 got a lot of bad raps... however some of it can be traced back to ill maintenance by the end user..
1. tuning a 6.0 for more horsepower was a sure-fire way to blow the headgaskets.. running them stock in their lower horsepower configurations typically found on vans and busses helped with this.
2. poor coolant maintenance resulted plugging up of the EGR cooler and oil cooler passages.
3. poor oil maintenance also resulted in plugged oil coolers..
the signifiance of a plugged oil cooler is that a truck pulling a heaby load with an engine that was aging resulted in more blowby and hotter oil.. there is no oil temp gauge on the dash.. the water temp rising up to 220-230 could easily result in the oil temp reaching the meltdown temp of 260.. what i mean by meltdown is the oil filter standpipe and related parts are plastic... if these melt, the engine is gone.. no rebuild, no fix.. you throw it away...
like most tier 1 emissions engines, adding EGR to the mix to help re-burn unburned fuel in the exhaust resulted in higher temperatures and more failures.. short trips where the engine doesnt warm up all the way results in EGR coolers rusting out on the exhaust side and coolant gets leaked into the exhaust.. obviously coolant in cylinders is a bad thing, you can steam pistons, lose enough to overheat or in extreme situations hydrolock the engine....
when you hear of people "bulletproofing" a 6.0, there is acompany clled bulletproof diesel that came out with specifically EGR coolers and oil coolers that were of much higher quality than the ford (International) factory parts... and along with that many people felt it necessary to also pull the heads and install ARP head studs which allowed for better holding power and less likely to blow headgaskets..
while you can read about many instances of failures on any forum or website, there were and are many 6.0's that have been well taken care of and continue to run every day.. International made these engines for both their own trucks and busses, and for ford..
I go back to the story of my 2 friends (husband and wife) who bought two box trucks brand new in around 2005/2006 with the VT365 (6.0).. and ran them to 400K before they traded them in on new ones a couple years ago.. they put a set of injectors in each truck at someplace around 250K if i remember right.. they kept up on their maintenance and didnt tune the engines.. while these trucks didnt win any races, they had very few days of downtime...
bulletproofing the EGR and oil coolers is something that can be done with the engine in the truck, and its not necessary to pull the cab to do it.. that said it does involve removing the turbo, intake manifold, fuel system, and the like to get to the parts.. a person with good backyard mechanic skills can do it with care... head studs are a little trickier but also something someone with good to expert mechanic skills can do...
I myself would buy a 6.0 in current working order in a heartbeat if the deal is decent on it.. in the ford configuration they were paired with the 5R110 transmission which is one of my favorite ford transmissions..
I wouldnt let the 6.0 stop you from your build unless it shows obvious signs of imminent failure like water in the oil / oil in the water, or excessive blowby, steam from the exhaust even in warmer weather..
while it may seem anemic in the hills, i would resist the temptation to install a tuner on it.. that is in fact asking for trouble..
the predecessor 7.3 responded very well to tuners as it has 6 head bolts per cylinder vs the 4 head bolts er cylinder on the 6.0.. no idea why IH did this esp for an engine they wanted to produce more power than the 7.3...
the assumed since the bolts were bigger and could be torqued down further that the holding power of the head would be better.. they were wrong... there just werent enough bolts.. the ARP studs clamp better and resist bolt stretch or incorrect torque that bolts can create thus why studding a 6.0 resulted in much better reliability...
thats my take an opinions and experience with the 6.0, take it as you will, everyone has different experiences...