Will this cover my factory bumper sensor holes or do I need to drill new ones?

You'll need to verify sensor hole alignment during test-fit. If holes don't line up, drilling may be necessary—mark and measure before committing. Factory sensor locations can vary by trim level.

Does this work with an aftermarket lower valance or stock bumper support?

This is a direct OEM-style replacement designed for factory support structure. If you've modified the lower valance or bumper bar, test-fit first to confirm clearance and mounting point compatibility.

Do I need to paint this or does it come ready to bolt on?

Chrome finish ships ready to install—no prep or paint needed. If your truck has been in an accident or the existing bumper bar is damaged, address that before installation so the cover sits flush.