Finally arrived, after a year and a half of delays, perfecting and redesigning the 08+ cobalt stage 4 kit is now available for purchase. The Treadstone manifolds are cast using the latest in investment casting method, utilizing bulletproof 304/347 stainless steel. The high thermal inertia and excellent heat retention of cast stainless steel provides the turbocharger with as much thermal energy as possible (lamens terms: faster spooling, higher efficiency). This effect raises the overall efficiency of the system! Plus since 304/347 stainless is rust resistant your manifold stays looking good for years to come (lamens terms: larger bling factor). The downpipe is hand crafted in the USA from 304 stainless steel and tig welded to perfection. For that perfect fitment every time. Flexibility + Power + Reliability = More Wins! -304 Stainless Cast Tubular Manifold -Turbosmart 38mm Wastegate -Stainless steel Downpipe and Dump Tube (Made in the USA) -Direct Bolt-On -Journal or Ball Bearing options Available Click Here For More Info!