Gearing up to "restore" my '03 4.6L Expy with 150K miles. Very well maintained, motor and trans in good condition. Plan is to restore interior and exterior to "showroom" condition. Vehicle is already lowered with Eibach/Bilsteins and 20" wheels/tires and upgraded radio with hands free, navigation, etc. Mechanical plan includes 4.11 gears, under drive pulley kit, 5 Star tuning, CAI and shorty headers. Debating on headers as it has been a while since owning a vehicle with headers; don't want to increase cabin noise. With the other modifications, I am not sure that whatever gain I might see from a set of shorty headers is worth the trade off for an increase in cabin noise but I don't know if there will be an increase in cabin noise. What say you that are running headers regarding increased cabin noise?