Will this bolt straight onto my truck without any modification?

Yes. This assembly mounts at factory points and uses the existing wiring harness — no drilling, cutting, or bracket fabrication needed. Drop it in and secure with OEM fastener points.

Do I need to order both left and right headlights, or can I buy just one?

You can buy individually. If you want a matching pair, order this left assembly plus the corresponding right-side headlight. Single-side installation is common for repairs or replacements.

What's the actual lifespan difference between this LED unit and a standard halogen bulb?

LED elements typically outlast halogen bulbs by thousands of hours, reducing replacement frequency over the truck's service life. Exact lifespan depends on driving conditions and usage patterns.