lbz wiring harness | eBay Save lbz wiring harness to get e-mail alerts and updates on your eBay Feed search results that fit your vehicle. Select Vehicle. Tell us about your vehicle to find the right parts faster. 2006-2007 LBZ Duramax Engine Wiring Harness 2500 3500 Silverado Seirra. Pre-Owned. $325 TBI Wiring Harness W/ECM 350 SBC 454 BBC TBI ENGINE SWAP Custom Standalone ECM / TCM harnesses (LB7, LLY, LBZ, LMM DmaxSwap has worked directly with StandaloneHarness to develop the cleanest solution for wiring your Duramax drivetrain for simple operation with nothing more than power, ground, ignition and cranking signals. This harness is the connection between the ECM/TCM and the engine harness as well as the transmission.