As much as the power plenum stages the power capabilities of the Impact, the rear block handles that transfer of power much like a hot-rodded car’s ported and polished intake manifold. This new valve house allows better air flow, efficiency, and power potential. The Power Block works best for higher power, especially those shooting heavy slugs, allowing higher speeds and power. 

FX Power Block Upgrade Kit w/ 720 Plenuum for M3's