Wiring Harness Information - LT1 Swap 1998 to 2002 Camaro/Firebird harness Wiring Info-New PCM Pinout info specific to 98, 99-02 F-body. 3/30/2013. 2004 Pontiac GTO Wiring Harness Info - Wiring harness info specific to the 2004 GTO LS1. wwwarness - Adam will rework most LS1, Vortec Truck, and F-Body LT1 Harnesses2007-2009 Vortec Harness · AFM Delete · Vortec 8 Info · Interesting Photo's I've Found PSI LT1/LT4 PCM Programming - Standalone Wiring Harness All PSI Harnesses are Made in the USA. In addition to wiring harnesses, you will find other components and kits for retrofitting older vehicles with these powertrains including PCM programming, Fuel Pump Kits, Engine Sensors, Extension Harnesses, Replacement GM connector pigtails and a complete line of hardware to complete your conversion needs!