Borla CrateMuffler S-Type Big Block Chevrolet Stock Output 396/402/427 V8.Borla(r)'s CrateMuffler is the world's first muffler purpose built to optimize the sound & power of crate and custom built motors. This CrateMuffler features the aggressive ATAK(r) sound. The mufflers are directional. The outlet can be identified by the mounting bracket welded to the endcap. The directional design provides custom sound, tuned for each engine family and will dramatically reduce, or eliminate drone on specified applications. Built from