Fork-N-Road, you are correct that just because heads were worked on separately is not a sure sign of a huge failure. It's pretty common practice to install new and improved valve guides if the heads are off. With the 6.0 rocker setup of one rocker arm to a bridge between two valves there are non liner forces that wear out the factory guides relatively quickly. There are newer valve guides that are much more durable. This motor could of had that done. We may never know for sure. It's just if I'm spending Belize's money I don't have a lot of confidence that the work done is going to give a big leap in reliability.
This is what I'm looking for on a 6.0 that was worked on for reliability.
-HPOP (High Pressure Oil Pump) - 2004.5+ not known for failure. 2003-2004.5 Known to fail and needs replaced.
-Injection High Pressure Oil Piping 2003-2004.5 - These years of motors have an entire different distribution piping than the 2004.5+ years have. Replace all piping under valve covers or avoid these manufacture dates all together.
-HPOP Snap to Connect fitting (2004.5+)- Updated Ford, not Doorman, one piece part.
-Dummy plugs (2004.5+) - Ford, not Doorman, updated part.
-Standpipes (2004.5+) - Ford, not Doorman, updated part.
-IPR (Injection Pressure Regulator) Updated screen with metal screen element, definitely not doorman or Ford plastic.
-HPOP Oil reservoir screen - Updated screen with metal screen element, definitely not doorman or Ford plastic.
- Fuel regulator - Ford, not ebay, blue spring update.
-EGR cooler - Bulletproof Diesel EGR cooler.
- EGR Valve - Replace with Ford, not Doorman. Some people clean them I'd want a new one.
-New oil cooler - Ford updated part, not Doorman, .
-Water pump - Bulletproofdiesel or Dieselsite With metal impeller.
-Turbo - Cleaned and stainless steel unison ring installed OR new Garret turbo.
-Turbo - Ford updated (rigid pipe style) oil fill and drain pipes.
-FICM (Fuel Injection Control Module) - Power supply side replaced with either Bulletproof diesel or FicmRepair.com. This is not a tune, only upgrading the power supply, although a 40hp ficm tune would probably be fine on non-head stud motor. I have this and it's nice.
-Coolant - Flush and Ford Gold replaced with a CAT EC-1 rated ELC coolant
-Coolant Filter - Install one.
-Alternator - Upgrade and increase capacity.
- Batteries - Best new ones you can afford. Make sure they are same age and brand.
-Serpentine Belt System - Replace all Idlers and tentioner. Install Ford, not Doorman/napa/autozone, belt.
- Vacuum Pump - Replace with Ford, not doorman/napa/autozone.
- Filters - Replace both fuel filters, Ford filters, not wix/napa/K&N.
-Head Studs - ARP head stud kit. (Engine removed) Not necessary in van if stock tune/never had a tuner.
-Heads - New or refurb with new improved guides.
-Heads - "ringed" heads. This is done mostly in high HP trucks and not needed in Vans with stock tune but I would consider it if the heads are off.
- Head gaskets - If new gaskets were installed which brand and model.
- Push rods - If heads came off. Ford issued a maintenance directive to install a shorter push rod. (part # from 6.4??)
- Lifters - If heads came off, The 6.0 roller lifters wear out. These are a very common part across several manufactures. Replace with name brand.
-injectors (over 150k motor) - Original or ???? I'd have to research as there are junk injectors out there.
- Engine electric harness - Ford part
- Glow plug harness - Ford part
- Injection harness - Ford part
- Glow plugs - Ford part
- Fan Clutch - Ford part
I'm probably forgetting something but that is the list I'd be looking for. Or that is what I would do If you handed me your 6.0 and said make it as reliable as you can.
2005 SMB RB 4x4 6.0 PSD
A rocket on the pad is safe,
but it's not what rockets are built for.