The stock grid heater design on the 6.7 Cummins is horrendous. Unlike the predecessor (5.9L) that featured a wide mount grid heater block between the intake manifold and intake plenum, which was relatively the same inside diameter as the manifold, the 6.7L iteration is actually built into the intake plenum/plate that has almost an hourglass design, creating a major bottleneck of airflow into your cylinders. Especially for those in warmer climates that really don't need a grid heater, why not eliminate this huge restriction? This upgrade will deliver a large increase in airflow, especially to cylinders 4, 5, and 6.