I know that this has been kicked around some in the past.
My truck is finished for the most part, but I still keep wondering.
Havent really found any good responses to this particular question.
NOT INTERESTED IN THE EBAY OR CHEAPY SETS.

Specifically:
Has anyone ever found any long tubes or tri-Ys for the S.D. 5.4?
Has anyone had performance gains with any of the name brand
tuned, shorty or mid-length sets?