LS2/LS3 swap
Thread Starter
Burning Brakes
Joined: Oct 2005
Posts: 1,020
Likes: 18
From: Anderson SC
LS2/LS3 swap
If I'm going to put an LS3 in my 07 LS2 Vette, what do I need to complete the swap. I will have the LS3 engine harness and computer. My car is also a manual but I don't think that matters. Thanks.
Melting Slicks
Joined: Oct 2003
Posts: 2,655
Likes: 5
From: Brea CA
ah...
I can't really help.. but Why are you doing that? I would think that the cost to do so would be really high... and buying a 08 with a LS3 and selling yours would cost less... and be worth more... Did your LS2 die? Why not the LS7?
and a TTT
and a TTT
Last edited by AtHomeSoda; Nov 28, 2009 at 02:03 PM.
Thread Starter
Burning Brakes
Joined: Oct 2005
Posts: 1,020
Likes: 18
From: Anderson SC
Well...already have the LS3. Would prefer the LS7 but cost too much for me to justify. I'm gonna do some work to the LS3 before it goes in and someone wants to buy my LS2. Kind of an easy decision for me to do the swap. Plus I won't need it as much in the winter months. And the biggest reason is my car is PAID OFF! 
Le Mans Master
Joined: Oct 2006
Posts: 5,078
Likes: 19
From: Cumming, GA
Thread Starter
Burning Brakes
Joined: Oct 2005
Posts: 1,020
Likes: 18
From: Anderson SC
Melting Slicks
Joined: Jul 2007
Posts: 3,097
Likes: 5
From: Brentwood World's first A6 in the 9's (including N/A, blower, turbo and nitrous cars) 9.950@139.267 CA
Here's a quick list of what's necessary:
- In your tune you'll need to make the PCM think it's running a larger displacement LS2 as well as altering the fuel injector settings if you'll be running LS3/LS7 injectors
- The MAF/IAT sensor is different so you'll need one from an LS2 along with the connector from the main wiring harness
- The cam position sensor is different between the LS2 and LS3 so you'll also need to remove that and splice it in to your existing wiring harness.
Hope that helps,
Christopher
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Thread Starter
Burning Brakes
Joined: Oct 2005
Posts: 1,020
Likes: 18
From: Anderson SC
Thanks. That's also an option. Wouldn't it be easier to just use the harness and computer and flash it to my car versus cutting up 2 harnesses? As I said, I have my LS2 sold and I'm sure he prefers the harness and computer be intact. But if I need to, I will use that option.
Melting Slicks
Joined: Jul 2007
Posts: 3,097
Likes: 5
From: Brentwood World's first A6 in the 9's (including N/A, blower, turbo and nitrous cars) 9.950@139.267 CA
Thanks. That's also an option. Wouldn't it be easier to just use the harness and computer and flash it to my car versus cutting up 2 harnesses? As I said, I have my LS2 sold and I'm sure he prefers the harness and computer be intact. But if I need to, I will use that option.
Also, if you swap PCMs the car has to be taken to the dealership and programmed with a Tech II scanner in order to match it with the rest of the car.
Thread Starter
Burning Brakes
Joined: Oct 2005
Posts: 1,020
Likes: 18
From: Anderson SC
Yup. You're exactly right. Luckily, I have a Tech 2! 
I do a lot of work on C5's and C6's so I bought one to eliminate most of the outrageous charges at the dealership. I've just never swapped in a newer engine and didn't know if there were any unforseen parts to change over. Thanks again for your input! 
I do a lot of work on C5's and C6's so I bought one to eliminate most of the outrageous charges at the dealership. I've just never swapped in a newer engine and didn't know if there were any unforseen parts to change over. Thanks again for your input!
Safety Car
Joined: Sep 2008
Posts: 4,296
Likes: 156
From: Location: Location: kAnSaS
the reason behind the maf is that it is a different animal. But other then that i see no reason not to leave everything like it is, swap the motors and tune the ECM thats in it now. The issue with swapping ecm's is you need to reprogram it to the vin. Dont think the tech 2 can do that without the Dealer computer to download it from. Hope thats not redundent info there. Good idea tho, the LS2 was ia awesome platform and can be beat on pretty hard, the LS3 is even more bulletproof taking even some hard FI abuse as well. Good luck, paul
