Can I reuse this gasket if I pull my header off later?

Yes, aluminum gaskets can be re-seated carefully if the sealing surface isn't damaged during removal. Clean both the head and header flange thoroughly with a gasket scraper before reinstalling. If you see any scoring or warping on the aluminum, replace it with a fresh gasket.

What torque spec should I use when bolting the header down?

Refer to your vehicle's service manual for the correct fastener torque sequence and specification. Over-tightening can warp the aluminum; under-tightening will cause exhaust leaks. Tighten in a cross pattern to ensure even clamping pressure.

Do I need to use sealant or gasket maker on this?

This gasket is designed to seal dry on a clean, flat surface. Using additional sealant is unnecessary and can create mess during future removal. Wipe both the head and header flange with a clean rag before installation to remove any oil or debris.