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C5 LS3 Swap

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Old Jul 17, 2025 | 12:52 PM
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Default C5 LS3 Swap

During a flash flood, 2003 50th Anniversary took on water. We found a rebuilt LS3 from a 2012 Vette and would like to swap it into the '03. Searching old forum posts for as much info as possible. Any advice- guides to follow, parts to buy would be greatly appreciated!
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Old Jul 17, 2025 | 01:29 PM
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Originally Posted by 89Corvette6spdFX3
During a flash flood, 2003 50th Anniversary took on water. We found a rebuilt LS3 from a 2012 Vette and would like to swap it into the '03. Searching old forum posts for as much info as possible. Any advice- guides to follow, parts to buy would be greatly appreciated!
Search is your friend.

https://www.corvetteforum.com/forums...-2000-frc.html
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Old Jul 17, 2025 | 05:49 PM
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Thanks Lucky, I appreciate your help. You must not have fully read my post, I have been searching. Already read that post. It doesn't go into detail of what adapters, harnesses, etc. need to be purchased.

Is this a common swap and also an easy plug and play engine?
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Old Jul 18, 2025 | 12:25 PM
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The swap has been many times, this article outlines the 'stuff' you need for the swap pretty well.

https://www.motortrend.com/how-to/16...than-you-think
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Old Jul 19, 2025 | 12:20 PM
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I just performed this swap into my 2004 convertible last year as I hydrolocked my supercharged LS1 in less than 6 inches of Hurricane Debby storm sewer overflow water less than two miles from my home. Below is a link to my story:

https://www.corvetteforum.com/forums...d-odyssey.html

Because my set-up is supercharged with a custom grind cam and headers, I needed some additional parts, however a straight LS1-LS3 swap should require mostly new gaskets, valve springs, T-stat/housing, sensors etc. In addition and most importantly you will need a Lingenfelter TRG-002 LSZ 58X-24X Trigger Wheel Conversion Control Module kit. Below is a link to their website/video explaining the unit:

https://www.lingenfelter.com/product/L460065397.html

My unit was mounted near the windshield firewall next to the battery den.






Last edited by MSG C5; Jul 19, 2025 at 08:49 PM.
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