what size K&N?

Check out JaysGN.com they have a ton of stuff for our cars and exact fit for the stock MAF 9" just make sure you have the cut the hole for the sensor in the neck of the filter
I've got a 14" cone filter (K&N style) that req'd the gas tank vent canister to be moved ... but it fits nice.

Beware, the 14" won't fit on the end of one of the hard MAF tubes unless they're shorter than normal.