Do I need to remove the header to replace this gasket?

Yes — the gasket sits between the header flange and the manifold. You'll need to unbolt the header and separate it from the manifold to access the old gasket, then clean both mating surfaces before installing the new one.

What should I do to the mating surfaces before installing?

Clean both the header flange and manifold face with a scraper or wire brush to remove old gasket material and carbon buildup. Bare metal-to-metal contact ensures the new gasket seats properly and prevents leaks.

Will this come with new bolts or fasteners?

Gasket only — bolts are not included. Reuse your existing header bolts if they're in good condition, or source new ones separately if needed. Torque specs are in your service manual.