Chevy GM LS3 Dual Plane 4150 MID-AIR™ MidRise Aluminum Intake Manifold [Black] and return line fittings

and return line fittings

They're available in round and oval styles

Use the stock Quadra-Jet carb or 500-650 cfm vacuum secondary carburetor

and have a maximum pressure of 7 psi with an externally accessible pressure relief valve

These rods incorporate a special doweled cap for specific cap-to-rod alignment and are profiled with extra clearance for stroker applications

Chevy GM LS3 Dual Plane 4150 MID-AIR™ MidRise Aluminum Intake Manifold [Black] and return line fittingsThe Speedmaster MidRise Air design features the identical plenum and runner design as the normal MidRise. The main difference is that there is an open area under the plenum chamber. This feature is sometimes called an air gap design. The air flowing under the plenum provides a cooler charge for the incoming air with less heat transfer from the engine. This cooler air charge provides additional power and torque.