1a. The new conversion headlight assemblies come with preinstalled adjusters and are already loaded with a high/low beam halogen bulbs. There is a plastic thing stuck on the end of the adjusters that needs to be removed before the headlights can be snapped into the grille shell. These will be used for the bulk of the adjustment in the headlight aiming. We set ours so the housing sat flush inside the grille shell, which worked out to be perfect.