Chevy SBC 350 1957-95 MID-AIR™ MidRise Aluminum Intake Manifold [Polished] They also help to insulate

They also help to insulate the carburetor from engine heat and provide clearance for linkages

The LS (Gen3/4) platform has many design benefits over the earlier SBC engine designs

they utilize a cotton gauze with aluminum mesh construction

full nylon braid

These rear-ends have a reputation for being tough to handle the abuse of Circle Track racing

Chevy SBC 350 1957-95 MID-AIR™ MidRise Aluminum Intake Manifold [Polished] They also help to insulateThe 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.