Do these mount at the factory attachment points?

Yes. These are designed to bolt directly to factory mounting points with no drilling or welding required.

Does this come with bulbs and wiring harness?

The headlights themselves are included. Confirm with your dealer or service manual whether you need a harness adapter for your specific year model.

Will these work with my truck's existing electrical system?

LED headlights draw less power than halogen. No rewiring is typically needed for factory systems, but have a shop verify compatibility if you're unsure about your truck's electrical setup.