http://aplsweb.com/Topics/Bens-Air-Box/Bens-Air-Box.htm BEN'S RAM AIR BOX MODIFICATION Justifications The stock intake system is too small for the 7.4L or even the 5.7L at full throttle and is a major constriction at most throttle settings in my opinion. If another supply line can be added without changing the existing, there will be two intake supply systems. All of this is in front of the air filter element, so it really doesn’t affect the smog system, that I know of. I decided to design a system to supplement the stock system and found all the materials at HomeDepot in the plumbing section (drainage, gutters and water meter boxes). Really got the idea after seeing a K&N system in a mag and thought I could do better and for less. This really needs to have the other end's restriction reduced too (change to dual exhaust).