LS3 in C5. Issues?

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Mar 9, 2019 | 12:22 AM

reh

Thread Starter

7th Gear

Joined: Mar 2019

Posts: 7

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LS3 in C5. Issues?

I’m new to the corvette world, be patient. Have a C5 dropping an LS 3 in it. What issues do I have to consider if any?Mounts/brackets aftermarket ?

Mar 9, 2019 | 12:32 AM

tblu92

Le Mans Master

Joined: Aug 2005

Posts: 5,375

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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---

Mar 9, 2019 | 02:12 AM

Tsumi

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.

Mar 9, 2019 | 03:11 PM

kmagvette

Burning Brakes

Joined: Aug 2005

Posts: 1,057

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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.

Last edited by kmagvette; Mar 9, 2019 at 03:44 PM.

Mar 15, 2019 | 07:44 AM

nsogiba

Drifting

Joined: Apr 2015

Posts: 1,893

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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

Mar 20, 2019 | 10:27 PM

reh

Thread Starter

7th Gear

Joined: Mar 2019

Posts: 7

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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.