Do I need to reuse the old gasket or replace it every time?

Replace it. Exhaust gaskets compress under heat cycles and lose sealing pressure over time. Install this new gasket during header work to ensure a tight seal and prevent exhaust leaks.

Will this work if I'm swapping in a different 4AGE variant?

This gasket is designed for both the carbureted 16V and the fuel-injected 20V 4AGE. Check that your header flange matches the gasket bore before ordering to confirm fitment.

What fasteners does this come with?

The gasket itself is included. Header bolts are not—use your original hardware or purchase separately if yours are damaged. Standard M8 or M10 bolts work depending on your header design.