I used AAW classic update like many have. I used a stand alone LS harness from PSI.if I was doing it again I would have went Speartech or BP automotive. That. Being said the AAW is a great harness for chassis. You'll use most the interior portion as well as front and tail harness. Only thing you won't use alot of is the engine side of the firewall forward from bulkhead. As Carl and others have suggested you can just repin. I chose to just remove the un used wires and took advantage of those I could. Think secondary oil pressure and water temp. My LS stand alone feeds my tach and speedo. AAW has a provisions for speed sensor you could use. But let the LS Harness do tach and speedo and it has an oil pressure and water temp to the LS Harness but no output for gauges. So I used AAW wires for oil and water. I added a port for the AAW oil pressure gauge sender and my LS water sender was in driver head so I put in the passenger head a water sender for the AAW water temp gauge.
AAW has an accessory pigtail for power door locks and Windows and a couple other extra IGN and Accessories.
I'm using those and chose to add an EATON 5 relay 10 fuse panel in my trunk. Ingot it feeding two heated seats, fuel pump, stereo amp and one circuit to LS ign for ECM.
That trunk mounted panel has a remote control contactor between it and the battery so without remote it can be cranked but no fuel no ECM.
Theft prevention was my idea here along with an added benefit of relays for heated seats and fuel pump as well as stereo amp.
Just some thoughts