Big Honking Air Filter
It is used in place of the standard air filter "assembly". It will just barely fit in the same space as far as length and height (diameter) without any covering. Some are making a heat shield to keep some of the underhood (turbo) heat away from it. Typically, it has been tried, with varying degrees of sucess, to lower exhaust temps. I think I have heard results from 0-200 deg lower. Hope that helped.
"Utah (no periscopes here)" Did you retire from the silent service?