Is Chet trying to improve performance without putting a turbo on it? If so he is pretty much wasting his time. It will help a little at sea level to improve exhaust and add a K&N in the Banks high rise housing but at any altitude these things are dogs !!!!! Been there done that, hence my username. A Banks, Hypermax, or ATS turbo will make a respectable truck out of it though. Several aquaintances added turbos and let me drive theirs. Night and day difference. Hope whatever he does works out for him. Is he looking at the Ford-Diesel website? Nice bunch of regulars on the 6. 9 forum.