If you plan on heavy towing, tuning, or have a heavy foot I would recommend saving up the money to bullet proof.
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The term BulletProof has no specific meaning. What the OP would need is a list of upgrades and modifications to improve reliability. That list would have meaning. Bulletproofing - no meaning.
I do agree that the factory 04.5-07 EGR coolers are weak. They need to be replaced with an EGR cooler from BulletProofDiesel.
I can even accept that head studs are an improvement, but more important than the studs is a true block deck as well as heads, AND the proper surface prep on both. I would even add o-ringed heads to that list (either new ones or straight/true/non-cracked used ones that have the o-rings properly machined in.
Then you have to have a fuel pressure gauge to make sure that the injectors are not jeopardized by low pressure.
Then the FICM needs to be upgraded. Possibly a higher amp alternator is needed as part of the FICM reliability upgrade.
Dummy plugs and standpipes need to be upgraded as the original ones were not reliable.
Then maybe the integral fuel pump relay needs to be replaced/fixed (it is integral to the Central Junction Box).
Then you need EC-1 rated ELC coolant and a totally clean coolant system (including an oil cooler that has no debris contamination). Some say that you need a remote located OEM oil cooler or an air/oil oil cooler, and it would be extremely nice......but I am one to believe that reliability is very possible with a meticulously maintained original oil cooling system. No doubt opinions vary on that subject!
Proper oil and ALWAYS use OEM oil and fuel filters.
Also, maybe the plastic "Y" under the degas bottle needs to be upgraded to metal.
Of course the quality of work is critically important as well.
etc.
Now maybe that is getting close to a list that means something for an 07.