don't know mac claims over 10 hp from their intake, the k&n imo a little better design and it has same power as stock til after nearly 4000 rpm and only a 3hp gain there http://www.knfilters.com/dynocharts/57-2527_dyno.pdf have thought of volant but haven't found any kind of dyno chart yet for them on a 4.0 ohv

 

unless you have other performance mods you will not feel any difference with an intake, it will just sound different. just a heads up.