Steelcomp,
I am a member of Fords Unlimited here in St. Louis, and we have 4 guys running 13 to 16 lbs on their Lightnings. I ask tomorrow at the "Blue Cruise", but I am not aware of bottom end problems on stock bottoms of the 5.4
But you know how it goes, the dealership has everyone looking for "warranty"....he-he.
Eric
