They are great Cummins swap candidates
Comfy cab, solid trans and strong suspension.
The amount of power they have with just a tune is unrivaled... Very fun when they run.I would buy a 6.4 if it came from someone reputable and was already gone through. otherwise I'd be scared to death of one. they're like the early v10 tdi engines of the ford world.
With early H&S tuning, yes. Even so, common sense goes a long way - we are not in 2011 anymore68rfe and head gaskets are a known 6.7 problem.