GM SINGLE PLANE
Next up on our list of single-plane intakes was the unit from Chevrolet Performance. Like the Holley single plane, the GM version featured a common plenum fed by eight individual runners. Unlike a tunnel ram, where the runners are all similar lengths, the single-plane design features four longer (outer) runners and four shorter (inner) runners. This means the runners are tuned to produce power at different engine speeds, with the shorter runners making power higher in the rev range. Run on the 415 stroker, Chevrolet’s single-plane intake offered peak numbers of
644 hp at 7,000 rpm and 546 lb-ft of torque at 5,200 rpm. Torque production at 4,000 rpm checked in at 483 lb-ft.