Choose size based on size of engine, headwork, and RPMs. Beautiful merged collector allows maximum extraction at high RPM while maintaining a good torque curve. Standard model comes with cheap paint; we recommend using our POR-20 (OK) or ceramic coating the header (Best!) for looks and durability.BTW, these units have slip-fit tubes that you assemble the header with. If they are too tight, the first step is to make sure there are no burrs on the OD and ID of the tubing, that may be causing it to hang up. If that doesn't work, brush on some Milk of Magnesia (not a joke) or Never-Sieze, it's slick and won't burn off! This is another low-buck garage tip.
Ceramic coatings: Ceramic Coating is a life EXTENDER, not a lifetime coating. In other words, you should expect the coating to make the pipes last longer than normal but don't expect the coating to be shiny or to last forever.
Normal lifespan varies according to where you live and if you drive the car in the winter in the salt zones. Salt zone, daily driver summer and winter the systems should last about 4 to 5 years normally.