Interlock Flex Section Size:3.5 Inches Most header kits will require

Most header kits will require this because the primary (front) O2 sensor is mounted further down the header rather than right next to the head like it is mounted in the factory rear manifold

if it comes back

RAINIER (2006 - 2007)

they are no longer enough

Dedicated forging

Interlock Flex Section Size:3.5 Inches Most header kits will requireThis is 100% 304 stainless steel and will not rust. Eliminates the whistling and failures commonly occurring in single wall or mesh style flex pipes. Works well in high heat applications. Available in 42mm, 2", 2. 5", or 3" diameters. 42mm is 4" long. 2" is 3" long. 2. 5" sections are 4" long. 42mm units work with 1 5 8" or 1 3 4" piping depending on whether you are welding into a slip fit or butt fit.