Does this need painting before installation?

Depends on your grille. If your factory grille is painted body color, plan to match or prime this molding first. Test-fit unpainted to confirm fitment, then prep accordingly.

Will this work with an aftermarket grille?

This is designed for factory mounting points. Aftermarket grilles vary in attachment and opening size — confirm your grille structure supports OEM trim placement before ordering.

What hardware is needed to mount this?

Mounting hardware is not included. Fasteners and clips depend on your grille assembly — refer to your truck's service manual or test-fit to determine what you need.