on a 4.7 i had stock, stock with a drop in K & N , a K & N CAI, and now the volant.
for power increase no better top end in my opinion than K & N cai, but since i went with the UNICHIP module, i had no choise but to switch to volanyt CAI, and i was extremely surpried to GAIN 2 MPG.
look on
ebay for a used 1, usually they can save you 100's for a slightly used 1.
i sold mine to a member for 75 & that including shipping was of like 27.
and mine was almost brand new, and i cleaned the filter and oiled it for him to, plus i gave a few other items free, just trying to help a member out.
gorilla