[olred07]

What kind of fuel systems are available for the 6.4's and which ones help with reliability?

 

[LovinPSDs]

There is alot in the works, but as far as ready to put in your truck right now I think the options are Elites HPFP and something on the low side like the Airdog II. Elites pump is supposed to be somewhere in the 20% range of more fuel.
RCD has twins in development and others do two I'm sure...