Gen 3 and 4 Layout

Gen 4 LS E38 Connections

Gen 3 LS E40

LS Harness Services​ (We will also modify GM 4 Cylinder ECOTEC and V6 Engine harnesses such as LU3 LV3 and LFX.  Please call for a quote.)

Gen III LS PCM Connections

​For $325.00 we will clean, degrease and modify any Gen 3 or 4 LS to make it Stand Alone.

Every LS Gen 3 or 4 Harness gets a Delphi Automotive covered fuse/relay block.  Included are relays for two Fans, and one for the Fuel Pump.   Fuse protection for all circuits and a 5' long OBD Port are a part of every finished standalone harness we ship.

Standalone rework turn around time is 2 weeks.

Gen 3 Engines are:  LS1 LS6 LM7 LQ9 LQ4 L59 L33 LM4 LH6 LS2 and LH6 engines.  These engines are controlled by the Red/Blue (411) or Green/Blue PCM or the E40 ECM.

Gen 4 Engines are: LS3 LY2 LY5 LY6 LH6 LMG LC9 LH8 L76 L77 L96 LFA LZ1 L92 L94 and L99 engines.  Most of those engines are controlled by the the GEN IV E38 ECM.

Some L96 Engines are controlled by the (3) Connector E78 ECM and will require the ECM connectors to be replaced with E38 connectors at an up charge of $125.00.  The E78 ECM will also need to be replaced with an E38.  Contact for a quote on the replacement ECM and required programming.


We are specialized in the correct modification of the Gen 4 LS E38 ECM and 6L80E or 6L90E powertrain harnesses.  The T43 TCM will maintain it's memory and shift the trans correctly after every shut down and startup.  

Whether your donor engine, ECM and harness came from a Silverado, Sierra, Yukon, Suburban or Escalade, you can be assured that your swap will run and shift as well as it did in the original vehicle.


Both Truck and Car based LS powertrains are supported.  Some examples of car engines are Camaro, Pontiac G8, Corvette, and Caprice PPV.


Simple 4 wire hook up (Batt Pos, Ignition, Ground, Fuel Pump). Also provided are outputs for check engine light, and an OBDII diagnostic data connector.  The easiest solution for gauges is to use CAN Bus plug and play gauges but there are alternatives to make factory or analog gauges work in your swap vehicle. Contact me for all Gauge hookup solutions on both Gen 3 and 4 swaps.


All connections are labeled with easy to read laminated plastic labels (that won't fall off or smear) and a printed guide for making the final connections to your vehicle is included.


All Grounds are centralized to just one ground lug that bolts to the engine block for an easier install.  


​Every Circuit/Connector is separated in the harness for an easy, tangle-free installation, that allows you to route the harness and finish as you choose for that full custom look.  Rewrap with GM Spec Tubing Loom and Tape is an available option.  DIY Loom Kits are also Available.


New fuse and relay blocks (with fuses and relays) are provided to make installation a painless experience.


When you drop off or ship your harness a complete checklist is discussed with you when it arrives. This way there are no surprises. If any connectors are damaged or missing you will know up front if there will be any additional costs beyond the basic service. Note that if connectors are missing it usually adds about $9 -$15 additional cost for each missing connector.


Harness can be set up for any transmission you choose.  It's possible to use a 6L80E, 6L90E, 4L80E, 4L60E, 4, 5 or 6 speed manual, Powerglide, TH350 or TH400.


All wire joints are soldered and shrink wrapped with adhesive shrink tubing. No crimp style butt connectors are used anywhere.


Programming assistance of the PCM/ECM/TCM for stand alone operation is available from

 Additional Questions?  Call Ken at (321) 604-1963