Will these bolt directly to my T660, or do I need custom brackets?

These are engineered for factory mounting points on your T660 — no custom fabrication required. Have your wiring diagram handy and test-fit before final installation to confirm clearance with any aftermarket bumper or grille work you've done.

Do these headlights come with harnesses, relays, or ballasts for the LED system?

The assemblies ship complete with LED projectors, but your vehicle's existing headlight wiring handles the connection. If your truck still runs halogen power, you may need a relay harness to properly support the LED draw — consult your service manual or a truck electrical specialist before you wire them in.

What warranty or return window do I have if these don't fit or fail?

Review ModSupply's return policy on checkout. Most electrical components have a 30-day window if DOA. Keep your receipt and photos of packaging in case you need to file a claim.