i own a 95 E350 EFI van which has an even more restrictive intake than the truck. no intake air horns in the small airbox just before the t-body, but has a small airbox mounted above the radiator that uses the same small airfilter as a 2L pinto. i converted the air intake to a K&N F350 filter and tucked it away in the driver side fenderwell after removing the battery and redoing the entire battery setup. and i fed it fresh air from an inlet in the airdam routed behind the bumper up thru the fenderwell.

to make this short, check into Unique Metal Products (UMP) Home Page for what many feel are the best air filters made. i shoehorned one under the van hood and used 4" alum tubing to do it.

neil