Dave and others, If you want to try a very little resistance filter with the original air box that will keep out small children, bugs and larger objects. I did this, Took an old filter, took off the filter part and left the screen part and stuffed some of the white christmas fiber material you put around the bottom of the tree down in the cavity where the filter went.Absoulty no air resistance. Worked great and gave me a sence of what Casey is doing. I was going to have Dirk build some air boxes out of SS, but cost If i'm not mistaken was about $300.00 + transporation. I think Caseys is a good deal . John hervey www.specialtauto.com