Speed Scene Wiring
LM7 Wire Harness
5.3L Vortec standalone wire harness — emissions or no-emissions, marine-ready programming available. Full GM diagnostic capabilities. USA made since 1999.
Start a BuildLM7 5.3L Wire Harness
The volume Vortec workhorse — standalone wiring for street, truck, and swap use, with emissions or no-emissions programming and marine options.
The 5.3 LM7 is the everyday choice in this family: more displacement than the 4.8, still compact versus a 6.0, and widely supported for parts and calibrations. Factory ratings land around 285–295 HP depending on application (Escalade/Sierra/Tahoe class vs Express/Savana vs TrailBlazer/Envoy).
We fabricate the harness with or without emissions and can program for marine use. An SSW harness with a full-capability GM controller preserves diagnostic access; stepping down to a smaller ECM / VCM / PCM usually means giving that up.
LM7 Engine Specifications
- Displacement
- 5.3L (5328cc)
- Compression Ratio
- 9.45:1
- Firing Order
- 1-8-7-2-6-5-4-3
- Bore x Stroke
- 96.01 x 92.00mm
- Valves per Cylinder
- 2 (stationary)
- Rocker Arm Ratio
- 1.7
Horsepower & Torque by Application
Cadillac Escalade, GMC Sierra, Tahoe, Suburban, Silverado, Yukon, Yukon XL, Avalanche
285 HP @ 5200 RPM
325 ft-lb @ 4000 RPM
GMC Savana (1500/2500), Chevy Express
295 HP @ 5200 RPM
330 ft-lb @ 4000 RPM
TrailBlazer, GMC Envoy XL
290 HP @ 5200 RPM
330 ft-lb @ 4000 RPM
EPA Approved Checklist
- VSS Circuit
- Diagnostic Link Connector
- Correct Emissions Connectors
- VSS Pigtail
- Alternator
- Tach Pigtail
Ready to Build Your LM7 Harness?
Custom-built to your spec. Emissions or no-emissions. Marine-ready. USA made since 1999.
Start a Build