Do I need two of these, or just one?

You'll need two total — one for each header. This listing is for a single gasket. Both sides of the Hemi require replacement at the same time to ensure an even seal.

What torque spec do I use when installing?

Refer to your vehicle's service manual for the exact torque sequence and foot-pounds. Over-tightening crushes the gasket; under-tightening causes leaks. Use a calibrated torque wrench.

Should I reuse the header bolts or replace them?

Header bolts stretch and lose clamp load. New bolts are strongly recommended — this gasket does not include hardware, so source them separately if needed.