Do I need new fasteners when I replace this gasket?

Your existing header bolts will work fine if they're in good condition. If they're stripped, corroded, or won't torque down cleanly, grab new ones—they're cheap insurance. Refer to your service manual for the correct torque spec.

Should I clean or prep the sealing surfaces before installation?

Yes. Use a gasket scraper or wire brush to remove all old gasket material and carbon buildup from both the header flange and cylinder head. Clean surfaces seal better and last longer.

Can I reuse the header bolts that came off my old gasket?

Most times, yes—as long as the threads aren't damaged and the bolts still clamp down with even pressure. If any bolt spins loose or feels stripped, replace the set. A single bad fastener will leak.