LS1 Conversion Wiring Harness When changing doing a LS1 Motor Conversion swap into a Third Gen Camaro or Firebird you will need a new modified harness. These harnesses are made for plug and play action, however there may be some modifications that may need to be done during installation for your specific applications. Harnesses are covered in black split loom tubing for a clean look. We will need your factory harness and the factory harness from the LS1 engine that you are installing sent to us.