Cody ,there more posts on this very topic and there are variations,all using the 6637 Napa filter.I used one 45 degree 4 inch elbow.Then inserted about a 3 to four inch piece of 4 inch pvc thin wall pipe into the filter,I was able to this after heating the filter slightly with a heat gun and then secured with two rivets.mount your elbow on your new filter assembly,and then you can insert another piece to the other side of the 45 elbow which can be inserted into the factory flex duct towards the turbo.Now having said that,I did not buy any clamps,just the elbow from lowes and I had a friend who had some4 inch pipe that I could have for free.The pipe will fit into flex duct,albeit tightly but that is what you want.I must emphasize there is a thick 4 inch and thin 4 inch pipe.Good luck.My total cost less than 60$.not bad,oh by the way just set the air temp sensor to the side and leave it connected
