Even though the design of the new 6.7L Power Stroke and Cummins are fundamentally different ... and reverse-flow cylinder heads are a first in this segment. However, these are only the most ...

Russ Flagle, the owner of Indy Cylinder Head, was kind enough to sit down with us and explain the ins and outs of his brand-new D12 head for Cummins 12-valve competition engines. A stock 12-valve ...