https://ssnperformance.com/4-e....xhaust-muffler-pipe-
Like the 6.0L Power Stroke, the 6.4L utilizes just four head bolts per cylinder. However, in an effort to improve head gasket reliability the outer diameter of the 6.4L’s fasteners were increased to 16mm from 14mm. Cut or loosen bolts and clamps on the old exhaust system.6. Install the front block-off plate and the rear block-off plate.7. Connect the new throttle valve pipe and other components.8. In a textbook example of what happens after nearly 100,000 miles of being tuned,