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 Build

LM7 5.3L Wire Harness

The 5.3 (5300) is a highly capable engine, great for mid-size engine compartments and is considerably smaller than the 6.0. The 4.8 and the 5.3 share the same block but the internals — crank and rods — are not the same. The intake is taught and ready for climbing. A taller plenum design / tunnel ram effect allows the air to hit the intake ports, yielding efficient power with a snap of torque.

Speed Scene Wiring fabricates this fuel injected wire harness, with emissions or without. If you require this engine in a marine environment, we can accommodate with the correct computer program. The nice thing about running a SSW wire harness and GM electronics are diagnostic capabilities. If you decide to roll with the smaller ECM / VCM / PCM (these are neat names for computers), you will lack the diagnostic capability.

Speed Scene Wiring 5.3L LM7 standalone wire harness — labeled connectors including 411 ECM, 4L60E trans, DLC, coil packs, and tails

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