Thanks Glenn.
With the lack of any real available performance parts for an '06 and up V10, I've about made up my mind to stay with what I have at present. There is no available Gibson exhaust such I've used on my last 3 trucks, no really good chip that will do much, and none in the trans shifting department where my F350 really needs it and the fact that the K&N really isn't much of a deal at $331 at Auto Anything - and the payback isn't there for spending well over $1200 for what you described. What really makes it bad is that the 10% ethanol winter blend has dropped my gas mileage from ~10.6 or about 1 mpg to 9.6. The truck on "real" gasoline, if available, gets 11.6