If you guys own an enclosed intake (i have AFE), ALL OF US have felt that nasty vibration feel/noise when we hit 3.5-4krpm!!! I HATE IT!!! A lot of ppl including myself thought it might be the intake pipe resting ont eh engine block, but if thats not it... what is it??? I found out its the vibration between the lid of the box and the box enclosure. I went to Home Depot and got rubber foam weatherstrip 3/16" thick (any thicker is too thick to close the lid) with ADHESIVE (sticky side). This stuff is usually used to prevent air drafts for doors. You pretty much just weatherstrip the lid of the box intake. It gets rid of the sound a LOT. For me, I can still hear the SOUND of the intake but the vibration is GONE!!! I hope this helps guys... Happy holidays and drive safely boys... and girls.