1996–2005 GM 3100/3400 Harness + Tuned ECM Package — No Core Required

1996–2005 GM 3100/3400 Harness + Tuned ECM Package

Complete simplified wiring solution — no ECM core required.

Built for 1996–2005 GM 3100 and 3400 V6 engines, this LMMF package gives you the major wiring and computer components needed for a clean, dependable demolition derby, race, off-road, or engine-swap build. No hunting down a usable ECM. No sending in a core. No trying to piece together mismatched wiring.

No core required • Kept in stock • Usually ships within 1–2 business days

Fits

• 1996–2005 GM 3100 / 3400 V6 engines
• 1996–1999 and 2000–2005 injector setups
• Demolition derby, race, off-road, and simplified engine-swap builds
• LA1-platform applications where applicable

What’s Included

• Professionally built simplified 3100/3400 engine harness
• All-new wiring, new connectors, and quality components
• Tuned ECM matched to the package
• Injector adapter, allowing the package to work across 1996–2005 injector setups

No Core Required

Your tuned ECM is included with the package. You do not need to send us an ECM core or return one after purchase.

In Stock & Fast Shipping

These harness and ECM packages are kept in stock and usually ship within 1–2 business days.

Why Choose an LMMF Package?

This is more than a replacement harness—it is a ready-to-run setup designed to remove unnecessary factory wiring and give you a cleaner, more reliable installation. Every harness is built with new wire and connectors, not brittle, worn-out junkyard wiring.

We simplify the wiring, match the ECM to the package, and build it for the abuse of derby, race, off-road, and swap use.

Before You Order

• Confirm that your engine is a 1996–2005 GM 3100 or 3400 V6.
• The included injector adapter supports both 1996–1999 and 2000–2005 injector configurations.
• Contact LMMF before ordering if you are unsure about engine year, engine family, or vehicle compatibility.
• See the related products below for compatible ignition, sensor, switch-box, and wiring accessories.

Plug it in. Fire it up. Send it.