This Billet Top Plate will improve air flow into the Intake Plenum. (1) 5.9L 24v Custom Billet Hi Flow Intake Plenum Top Plate.19.75" Long / 3.80" Wide /. The item "Billet Air Intake Manifold Plenum Top Plate Cover for 98-02 ISB Cummins 5.9L 24v" is in sale since Tuesday, November 26, 2019. This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts\Air Intake & Fuel Delivery\Air Intake Systems". The seller is "npboosted" and is located in Campbell River, British Columbia. This item can be shipped worldwide.