And while vintage 409 manifolds had road draft tubes, Edelbrock's Chad Magana cleverly hid a PCV valve at the rear of the intake manifold for more effective crankcase vapor and pressure evacuation.

As a result, Edelbrock created the RPM Air-Gap LT1 intake manifold (p/n 7107) to significantly improve output between 1,500-6,500 rpm, while also pulling the plenum away from the splashing oil in ...

D16 Power - Edelbrock Intake Manifold Edelbrock's New D16Y Intake Manifold MotorTrend StaffWriterMar 14, 2004 See 1 Photo ...

348/409 intake runner differences, from top: rare Z-11; high-perf, large-port 409; and 348/low-perf 409. The three different configurations have different size ports and intake manifold bolt patterns.