PIT66 LED DRL Headlights Assembly for 1999-2007 GMC Sierra - Brighter

In this review the PIT66 LED DRL Headlights Assembly is evaluated for owners of late 1990s to mid-2000s GMC trucks and SUVs. The bottom line: this direct-replacement pair is best for non-Denali Sierra and Yukon owners who want a brighter, more modern look and improved nighttime visibility without modifying the vehicle. The review focuses on fit, build quality, the added LED DRL feature, and durability, and concludes whether it is a practical upgrade for common GMC models.

Key Features

• Wide compatibility: Designed to fit many GMC Sierra 1500, 1500HD, 2500, 2500HD, 3500 and Yukon model years, reducing the risk of ordering the wrong assembly.
• LED DRL upgrade: Built-in LED daytime running lights offer a cooler, brighter look and increased visibility during daytime driving.
• Micro-prism reflector: The internal reflector and chrome finish increase light reflectivity so oncoming traffic notices you sooner at night.
• Sturdy sealed housing: Heavy-duty plastic housing with a fully sealed design and one-way vent helps resist weather and reduce moisture buildup for longer life.
• Direct replacement set: Supplied as a complete pair including driver and passenger sides for straightforward replacement without body gap issues when installed correctly.

Who It's For

This assembly is aimed at owners of 1999-2007 GMC Sierra 1500 series and 1999-2006 Yukon models (including Yukon XL variants) who want an OEM-style fit with updated LED DRL lighting. It suits people who prefer a plug-and-play replacement that improves brightness and appearance without extensive wiring or fabrication.

It is not intended for Denali trim vehicles or for non-classic 2007 Sierra models. Professional installation is recommended, so those uncomfortable with headlight alignment or connector work may want to plan for shop installation.

Pros & Cons

Pros

• Improves daytime and nighttime visibility thanks to the added LED DRL and reflective chrome interior.
• Full sealed housing and one-way vent design reduce moisture issues and improve durability in wet conditions.
• Direct-replacement pair fits a wide range of GMC Sierra and Yukon years and includes both left and right units.

Cons

• Bulbs are not included, so buyers must purchase compatible bulbs separately.
• Not compatible with Denali trims and only fits 2007 Classic Sierra models, which limits fitment for some owners.

Specifications

Brand	PIT66
Fitment	1999-2007 GMC Sierra / 1999-2006 GMC Yukon (see model notes)
Included	Complete pair: Driver (Left) and Passenger (Right)
Lighting feature	LED DRL (Daytime Running Light)
Housing	Fully sealed heavy-duty plastic with one-way vent
Interior finish	Micro-prism reflector with fine chrome plating
OEM part numbers	15166756, 15166757, 125104011, 125103011

Our Verdict

The PIT66 LED DRL Headlights Assembly is a practical upgrade for compatible GMC Sierra and Yukon owners who want improved brightness and a modern DRL look with a robust sealed housing. It offers good value when matched to the correct model years, but buyers should note bulbs are not included and Denali or non-classic 2007 models are excluded from fitment.

Frequently Asked Questions

Will these fit Denali trims?
They are not compatible with Denali trims; choose a unit specified for Denali if required.

Are bulbs included?
Bulbs are not included; you will need to purchase compatible bulbs separately before installation.

Is installation difficult?
They are direct replacements and designed to avoid extra gaps, but professional installation is recommended for proper alignment and sealing.