Single Plane EFI 4500 Split-Design Race Intake Manifold- GM LS1/LS2/LS6 Black Finish with Fuel Rails HolleyThe Ls Race single plane intake manifold is designed for hi performance racing engine applications, 5. 3 to 6. 2+ liter displacements, N A or with power adders. The large volume 4500 plenum and optimized runners provide airflow potential for Hi RPM engines with max power at 7500 8000+ RPM. The manifold with An 8 fuel rails fits Gm Ls Gen Iii engines with cathedral port heads and has a 4500 Dominator style carb flange for carburetors, EFI throttle