I've been looking at air intakes for quite some time now something like I saw on this page Best Cold Air Intakes for 6.4 Powerstroke Review in 2020! , doing as much research as I can. I've been looking for the best free-flowing, best filtering, most turbo whistle combo that I can find. It sounds like the Scotty II was the best, but they don't make that anymore, so that's out of the question. I've looked at the aFe stage I, s&b, BHAF, and many others, but I still can't find the answer. I'm willing to build my own system and cut some holes if that's what it takes to get the best system. I've heard that a system that has a filter attached to a 6"-4" reducer into the air intake tube does the trick, but I'm still in the dark. Let's hear some opinions on this one. Thanks to everyone in advance.