Installs for NP233 (manual shift), NP243 (electronic shift with dash buttons), NP246 (electronic Autotrac 4WD)
📐 Dimensions
Exterior
Wheelbase Light Duty:
130.0 in (Standard Bed), 144.5 in (Long Bed)
Wheelbase Heavy Duty:
130.0 in (2500HD), 130.5 in (3500 Single Rear Wheel), 145.5 in (3500 Dual Rear Wheel)
Bed Lengths:
6.5 ft (Standard), 8 ft (Long)
Weights
Curb Weight Range:
Approx. 4,500 - 7,000 lbs (depending on configuration)
Towing Capacity Max:
Up to 10,000+ lbs (properly equipped)
Payload Capacity Max:
Up to 4,000+ lbs (properly equipped)
🛡️ Safety Features
Ratings
NHTSA Rollover Resistance:
3-star (typical for this era, varies by configuration)
Iiihs Crash Test Ratings:
Good in frontal offset (typical for this era, specific results may vary)
Active Features
Active Safety Features Available:
Anti-lock Braking System (ABS) standard on most models, available on all.
Passive Features
Passive Safety Features:
Front airbags, seat belts with pretensioners, reinforced safety cage construction.
💡 Technology Features
Infotainment
Infotainment Systems:
Factory AM/FM stereo with cassette and/or CD player. Optional premium sound systems. Basic HVAC controls (manual or optional automatic climate control).
Driver Assistance
Driver Assistance Features:
Cruise control standard on most models. Optional parking assist sensors (rear).
Connectivity
Connectivity Options:
Limited by modern standards. Primarily focused on vehicle operation and basic audio. Trailer wiring provisions common.
Diagnostics
OBD Ii Support:
On-Board Diagnostics II (OBD-II) compliant, allowing for engine code scanning and real-time data.
🔧 Maintenance
Service Intervals
Oil Change Interval:
Every 3,000 - 7,500 miles or 6 months (depending on oil type and driving conditions - refer to manual for specifics).
Engine Coolant Flush:
Every 30,000 - 50,000 miles or 2-3 years.
Spark Plug Replacement:
Every 60,000 - 100,000 miles (depending on spark plug type - platinum/iridium recommended for longer life).
Fluid Specifications
Engine Oil Spec:
API Service SG, SH, or SJ; SAE 5W-30 or 10W-30 (refer to manual for temperature ranges and specific engine requirements).
Engine Coolant Spec:
GM P/N 12345773 (Green), or equivalent Dex-Cool compatible coolant (orange) if specified.
Brake Fluid Spec:
DOT 3
Known Issues
Common Issues Engine:
Intake manifold gasket leaks (Vortec V6/V8), oil pressure sending unit failures, exhaust manifold leaks, catalytic converter failure, minor oil leaks (rear main seal, valve cover gaskets).
Common Issues Transmission:
4L60E failure modes (e.g., torque converter shudder, slipping), transmission cooler line leaks, transmission control module (TCM) issues.
Common Issues Chassis:
Front suspension component wear (ball joints, tie rod ends), rear axle seal leaks, brake component wear (rotors, pads), ABS sensor failures.
Common Issues Electrical:
Instrument cluster failures, HVAC blower motor resistor failure, body control module (BCM) glitches, power window/lock motor failures.
📚 Vehicle History
Brand Heritage
Chevrolet Truck Legacy:
Chevrolet has a long and storied history of building reliable and capable trucks dating back to the early 20th century.
Model Evolution
C K Lineage:
The C/K designation has been used for Chevrolet's full-size trucks for decades, evolving through many generations.
Gmt800 Generation Start:
1999 saw the introduction of the entirely new GMT800 platform, replacing the aging GMT400.
Production
Manufacturing Locations:
Various GM assembly plants in North America (e.g., Fort Wayne, Indiana; Janesville, Wisconsin).
🏆 Awards & Recognition
Recognitions
Truck Of The Year Awards:
While specific awards for the 1999 model year may not be as prominent as later iterations, the GMT800 platform as a whole was well-received for its design and capability.
Longevity Reputation:
These trucks are widely recognized for their durability and ability to be maintained and repaired over many years, contributing to their strong resale value and owner loyalty.