Do I need to clean the header and manifold surfaces before installing this?

Yes. Scrape away old gasket material and carbon buildup with a gasket scraper or soft wire brush, then wipe clean with a lint-free cloth. Any residue will prevent a proper seal and cause exhaust leaks.

Should I use sealant or adhesive with this gasket?

Most installs work dry — clamp pressure alone seals the aluminum gasket. If you have a history of header leaks or extreme vibration, a thin bead of high-temp gasket sealer on the gasket face before installation can add insurance, but it's not required.

What torque spec should I use when bolting the header back on?

Refer to your vehicle's service manual for the correct fastener torque — specifications vary by bolt size and material. Uneven tightening causes gasket failure, so use a criss-cross pattern and work in stages.