on a 6.0 most of the Ford guys will tell you do not ever use anything but Motorcraft or Racor (who makes the Motorcraft) filters anywhere on the truck.
When I had a 5.9 the FASS was a popular upgrade because tuned trucks tended to burn up the lift pumps pretty quick. The 6.0 does not suffer lift pump failure at the same rate.
On the 6.0 most injector problems are oil related, or FICM related. I can see how more fuel pressure in the rail would help overall, just curious how much difference it would really make.
2013 Coachmen Freedom Express 320BHDS pulled by a 2005 F250 King Ranch CC
A rainy day camping is better than a sunny day at work.