Borla CrateMuffler Small Block Chevrolet ATAK 2.5in Offset/Offset 14inx4.35inx9in MufflerBorla CrateMuffler Small Block Chevrolet ATAK 2. 5in Offset Offset 14inx4. 35inx9in Muffler BORLA(r)'s CrateMuffler(r) is the world's first muffler purpose built to optimize the sound & power of crate and custom built motors. This CrateMuffler(r) 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