Well I've noticed that my fuel pressure has dropped about 1 psi over the last two weeks and this morning when I went to start the truck the LP sounded like it was straining. I'm wondering if it may be the PS/MMO mix I'm using. I put about 16 oz in with the fillup 2 weeks ago and now the issues. The bottle says it's good for 50-100 gallons and I used 1/2 bottle when I filled up. I'm going to check my filter but it was just changed at my last oil change.
I guess it may be FASS or Holley Blue time........

 

I seriously doubt its the Power Service, I usually use quite a bit as well. With fuel quality these days, you almost can't use too much.

 

I am running the quad race box on my 2004 also.I bought the FASS system and love it.My fuel pressure was way down running the stock lift pump.With the FASS system and WOT in the 140 hp postion my fuel pressure stays a steady 12-13 psi.coobie