Here you go! I got mine from our local Carquest for $56. The Napa wanted $70, and didn't have it in stock. If you want an Outerwear, the part number in this link is out-dated. The correct part number is now 20-1085. Just go on their site and search for that number.
http://www.cumminsdatabase.com/read.php?id=15
BTW, I made one of the heat shields that is shown. Just look at the template, print it out, trace it onto a piece of 12 guage sheet metal, burn it out with the plasma, sand it, drill the holes for the factory airbox fasteners, score the bend line with a cutoff wheel, bend it, fill the scored bend with weld, paint, and install. Took about 2 hours start to finish. Turned out really well, and if you're not a great welder, it's OK. the weld will be hidden. Just put a vaccuum cap on top of the shock stud to get rid of the rattle.

Sorry to hijack this thread! I noticed no difference when the factory airbox is still in place. We secretly pulled a buddy's off in hopes it would freak him out, but it made no real difference. I haven't removed mine, and probably won't. It whistles plenty with the BHAF. I don't want it any louder.

 

This is how it was on my 04.5. I don't know if it would be the same for most of them or not. The first pic shows the retaining ring (arrow). I started from that side with a small screwdriver. Once it was lifted out of its groove, I worked it around the rest of the way with my finger and it fell right out along with the ring. The second pic shows the ring missing. And if you have an air filter like mine (3rd pic, Afe stage II) and the ring missing- she sings pretty SWEET! I like it, but it's all prefrence.





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