Will this bolt directly to my truck without drilling or modification?

Yes. This mirror uses factory mounting points — no drilling or brackets needed. Unbolt the old one, bolt this one on.

Does the LED signal work right out of the box?

The signal light is integrated into the mirror assembly. Wire it to your truck's signal harness (follows OE routing) and it'll function immediately.

How stable is the mirror at highway speed with manual adjustment?

Manual mirrors are rigid once positioned. Tighten the adjustment mechanism fully before driving — no drift or vibration at speed.