Yes the FASS on a 6.0 is a good fuel upgrade if you are planning to run larger injectors in the future. I would suggest a regulated return such as an ITP RR before upgrading to a FASS. It will allow for better fuel flow through the heads when you do upgrade to the FASS. The only thing I don't really care for on the FASS system is the replacement fuel pickup tube. There is a cheesy gasket that goes in the tank over the pickup tube, that tends to leak.