LS engine swap can I use the OEM wiring harness?

1977 CHEVROLET CHEYENNE
39,000 MILES • 6.6L • V8 • 4WD • AUTOMATIC
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D_NORTH
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Hey there!! You guys rock!! LS Swapping Chevy Square Body I was wondering if I got a 5.3 LS/LM7 can I use the wiring harness it comes with or do you recommend using Holley Terminator X. The reason I ask is because the Terminator X is super expensive. If you do not recommend using the OEM wiring harness is there another option that isn't as expensive as the Terminator X?
Aug 19, 2021 at 5:00 AM
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KASEKENNY
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This is a great question and you came to the right place because we actually have a whole video series on swapping an LS and what is needed.

Here is the link to the first video in case you haven't seen it. There are about 15 of them so they should stack up in your que as you view them.

https://youtu.be/NyX6FwLYDuc

However, I am also going to ask Ryan (who is in the video) to chime in on this because nobody will know better than him.

Please allow about a day for him to respond as he is not normally on here answering questions for members.

Thanks again and I am sending him a message now.
Aug 19, 2021 at 10:56 AM
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RYAN L
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Hey there! Thank you so much for using 2CarPros!

Yes you can use the stock harness if all your connections are stock. If they are not stock, like if you have aftermarket injectors sometimes there are adaptors you can use. If you do go with the stock unit you may have to make some wires longer or shorter depending on your routing.

The harnesses I really like are made by https://www.bp-automotive.com/ those are made in the USA and use stock quality GM connections. They are the way to go if you ask me.
Aug 20, 2021 at 9:45 AM
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D_NORTH
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Dude, thank you so much! Very informative answer and I will 100% take your recommendation. Keep on rocking Ryan!
Aug 23, 2021 at 6:57 AM