LS3 in C5. Issues?
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
I would never attemp this mod by yourself---It is worth the extra cash to have someone who has done these changes do them--If you plan on using your exsisting ECM it can be converted to run a LS3 engine but only a tuner with HP or EFILIVE can convert your existing tables to work on a LS3 ---Yeah it will start and run just OK but there are so many tables such as the VE table the sprark tables that are far different than your existing engine's tune---
Drifting
Joined: Nov 2016
Posts: 1,660
Likes: 365
From: SF Bay Area
http://www.superchevy.com/how-to/eng...han-you-think/
Give that a good read, and then increase how difficult it sounds by a factor of 10 to 100 if you are new to engine swaps and do not have the proper equipment and working area.
Give that a good read, and then increase how difficult it sounds by a factor of 10 to 100 if you are new to engine swaps and do not have the proper equipment and working area.
Burning Brakes
Joined: Aug 2005
Posts: 1,057
Likes: 11
I am in the middle of this project right now. I had the LS3 built, so I went with the 24 tooth reluctor wheel to avoid the EMC converter box issues. Your current mounts will work just fine, except you will need to grind a bit out of the right side mount that bolts up to the engine. I went he Dry Sump route which causes a whole slew of additional challenges, especially if you like to over-do things as I apparently do.
You will also need to get some wire harnesses for the Crank and Knock sensors since they are in different locations than on the LS6. I got mine from Casper. If you use an LS3 intake manifold, then you will also need adapters for the injector connections.
Also, if you use the LS3 intake, on the back there is a tab you need to break off for the vacuum pick-up. Do this before the engine is installed; guess who forgot to do that.
Other than that, it is pretty straight forward.
You will also need to get some wire harnesses for the Crank and Knock sensors since they are in different locations than on the LS6. I got mine from Casper. If you use an LS3 intake manifold, then you will also need adapters for the injector connections.
Also, if you use the LS3 intake, on the back there is a tab you need to break off for the vacuum pick-up. Do this before the engine is installed; guess who forgot to do that.
Other than that, it is pretty straight forward.
Last edited by kmagvette; Mar 9, 2019 at 03:44 PM.
Drifting
Joined: Apr 2015
Posts: 1,893
Likes: 295
From: Buffalo NY
Tons of good threads out there on the topic. It has been documented on here about a half dozen times if you search.
Here is my build thread.
https://www.corvetteforum.com/forums...to-c5-frc.html
Here is my build thread.
https://www.corvetteforum.com/forums...to-c5-frc.html
Thread Starter
7th Gear
Joined: Mar 2019
Posts: 7
Likes: 0
Thx to all for the responses. I needed to be a bit more clear about my project. The C5 drivetrain and unibody are under a ‘46 Chevy truck. I guess I was asking if the LS3 will bolt right up to the existing torque tube/motor mounts, etc.
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Drifting
Joined: Apr 2015
Posts: 1,893
Likes: 295
From: Buffalo NY
Keep in mind also that OP will need to grind the C5 Engine mount stands (cast aluminum) to clear certain bosses on the LS3 block. 20 min job, easy