Holley Hi-Ram Plenum Plate Conversion Nitrous Express NX NX940 - USA-NX940 - The Holley Hi-Ram Nitrous Plates take full advantage of the Holley Hi-Ram intake manifold. The Hi-Ram Plenum Plate bolts right in between the upper and lower intake manifold making the install a super clean and quick. Hi-Ram Nitrous Plates allow you to inject nitrous and fuel above each cylinder from the side of the runner providing direct port-like distribution without having a flow restricting nozzle or spray bar. The Hi-Ram nitrous plate is made in the USA from billet aluminum with passages machined directly into the plate so there is no need to worry about spray bars breaking or spinning. Features of the Holley Hi-Ram Nitrous Plate 50-400 WHP Made in the USA Machined out of billet aluminum  No spray bars