Do I need new bolts or fasteners to install this?

The gasket itself mounts using factory bolt holes; fastener condition depends on your existing hardware. If your header bolts are seized, corroded, or stripped, you'll need replacements—grab a set rated for exhaust manifold temps before you start.

What's the best way to prep the mating surfaces before installation?

Clean both the cylinder head and header surfaces with a wire brush or gasket scraper to remove old gasket material and carbon buildup. Wipe down with a clean rag—you want bare metal contact, no oil or debris. Don't need to sand or prime; just clean and dry.

Can I reuse the old header bolts, or should I buy new ones?

If they came out clean and the threads aren't stripped, you can reuse them. But exhaust bolts see constant heat cycling—if any show corrosion, seizure damage, or thread damage, swap them out. New fasteners cost less than a stuck bolt headache.