We have a 2006 Pontiac gto ls2. can we use a stock wiring harness or do i need a special wiring harness.
Yes you can. I have a 1965 cutlass I installed a 2002 ls1/4l60e trans. I built my on harness using the factory harness. Here is the catch in my case I mounted the ecm to inner fender by doing this I did not have to cut and splice wire onto the existing ecm connector wiring. What that means there are only a hand full of wires needed to connect to ground and 12+ to make these engines run in your classic. None of these connections require a professional soldering job and wrap to function properly. If you plan locate the ecm hidden inside you will need to splice wires onto the existing harness. That needs to be done by a wiring expert. Some of the low volt wires that feed the fuel rail etc can cross talk if not built correctly. I'm no wiring expert but I get by. I'm planning a lsx in my nomad project and if I decide to hide everything I will be seeking the help of a harness guru. There are several over at ls1tech that you can send your harness to and they will build a custom one for you and program your ecm to delete the un needed stuff. There are also tons of wiring data on the ls1tech site should you decide to build your on harness. wait4meprefromance does a mail order tune fo 84$ includes return shipping. http://www.wait4meperformance.com/We have a 2006 Pontiac gto ls2. can we use a stock wiring harness or do i need a special wiring harness.