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Topic: C3 Corvette LS Swap 6 Speed Manual Transmission Swap

C3 Corvette LS Swap 6 Speed Manual Transmission Swap (1/3)
 4/20/20 2:18pm
Adam WartellLifetime Member
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Eagleville, PA - USA

Vette(s):
Used to own a 1979 Corvette now owned by JB79


Joined: 11/1/2001
Posts: 15461

1969 Chevrolet C3 Corvette LS Swap 6 Speed Manual Transmission Swap at V8 Speed and Resto Shop 

This 1969 Chevrolet Corvette Convertible came to the V8 Speed and Resto Shop in need of some serious power, performance, and reliability upgrades.   This C3 Corvette was powered by a non-original and well worn 350 cubic inch V8 backed by a Muncie 4 speed manual transmission.    The goal was a Corvette LS Swap to add modern power to this C3 Corvette.    A C3 Corvette LS Swap seems to be a simple job at first glance, but the more you investigate, you'll see that a C3 Corvette LS Swap isn't quite so simple. 

Video is in 3 parts. Parts 1, 2 & 3 and their descriptions are all below...

Part 1

The V8 Speed & Resto Shop team addresses the fitment issue of the LS3 V8 swap, as well as the steps needed to perform a Tremec T56 Magnum 6 speed manual transmission swap into the C3 Corvette.    The challenges included fitting the off-center LS3 engine under the hood, as well as fitting the Tremec 6 speed manual transmission into the C3 Corvette chassis.    We sourced our LS swap engine from GM Performance Parts, and a Tremec T56 Magnum 6 speed manual transmission, clutch, bellhousing, and shifter from Modern Driveline.  

The V8 Speed and Resto Shop team fabricated a custom transmission tunnel to accommodate the T56, and special motor mounts were used to mount the LS3 engine.   Exhaust is handled by Holley cast iron header manifolds, and the front LS swap accessory drive system is from Holley.   A Holley Dominator EFI system manages the engine and fuel system.  

Our crew rewired the Corvette with modern wiring, and added a custom fabricated air intake system and K&N air filter to allow the Corvette LS swap to breathe freely. 

In addition, the Corvette needed some maintenance.   For example, the C3 Corvette's headlight doors are not working, and the windshield wiper door was also not working.   These items rely on vacuum for power, and they wear out over time.  The V8 Speed and Resto Shop team elected to install a Detroit Speed Corvette Headlight Motor conversion and a Detroit Speed Windshield Wiper conversion as well.   These convert the vacuum systems to electric headlight motors and an electric wiper door.

The V8 Speed and Resto Shop team performed other upgrades to the C3 Corvette, including a dashboard gauge set from Dakota Digital and a modern air conditioning system from Vintage Air.   A Custom Autosound bluetooth stereo provides enhanced connectivity and better sound quality.    

Other performance upgrades include a Hydroboost brake system from Hydratech and 6-piston Wilwood disc brakes.    A set of 17 inch YearOne aluminum Corvette style rally wheels were added along with performance tires. 

The LS3 engine swap exhaust system was custom made, including a V8 Speed and Resto Shop fabricated stainless side pipe exhaust system filled with Magnaflow sound deadener.  

Once completed, the V8 Speed and Resto Shop crew created a base tune to get the 480 horsepower LS3 engine running, and then used both a laptop computer and the Holley Dominator's self-tuning ability to refine the LS3 engine tune.   In the end, the Corvette LS Swap was a complete success, and the owner was able to drive this freshly repowered C3 Corvette home nearly 1000 miles without an issue. 

Part 2:

CHAPTERS

0:50 Detroit Speed C3 Corvette Electric Headlight Motor Conversion

1:34 Detroit Speed C3 Corvette Electric Windshield Wiper Door Conversion

3:02 Tremec T56 Magnum 6-Speed Manual Transmission Overview

In this episode, the V8 Speed and Resto Shop crew installs some improvements from Detroit Speed.   For example, the 1969 C3 Corvette's headlight doors are not working, and the windshield wiper door was also broken.   These items rely on vacuum for power, and they wear out over time.  The V8 Speed and Resto Shop team elected to install a Detroit Speed Corvette Headlight Motor conversion and a Detroit Speed Windshield Wiper conversion as well.   These convert the vacuum systems to electric headlight motors and an electric wiper door.

Next,  The V8 Speed & Resto Shop team addresses the fitment issue of the LS3 V8 swap, as well as the steps needed to perform a Tremec T56 Magnum 6 speed manual transmission swap into the C3 Corvette.    The challenges included fitting the off-center LS3 engine under the hood, as well as fitting the Tremec 6 speed manual transmission into the C3 Corvette chassis.    We sourced our LS swap engine from GM Performance Parts, and a Tremec T56 Magnum 6 speed manual transmission, clutch, bellhousing, and shifter from Modern Driveline.  

Next time, The V8 Speed and Resto Shop team fabricates a custom transmission tunnel to accommodate the Tremec T56 6-speed manual transmission, and the LS3 swap continues with special motor mounts to mount the LS3 engine.    The engine will be installed along with a Holley LS front accessory drive system and more. 

Part 3:

CHAPTERS - 

2:45 What is a Chevrolet LS3 Engine?

7:49 Holley Dominator EFI System Explained for LS Engines

9:26 Fuel System Upgrade

In this episode, the V8 Speed and Resto Shop crew builds a custom fiberglass transmission tunnel to fit the Tremec T56 Magnum 6 speed manual transmission swap into the C3 Corvette.    The challenges included fitting the off-center LS3 engine under the hood, as well as fitting the Tremec 6 speed manual transmission into the C3 Corvette chassis.    We sourced our LS swap engine from GM Performance Parts, and a Tremec T56 Magnum 6 speed manual transmission, clutch, bell housing, and shifter from Modern Driveline.  

CONTACT US: http://www.v8speedshop.com

This LS3 will be running a Holley Dominator EFI system to manage the engine.    A Holley LS Swap oil pan is installed to clear the C3 Corvette frame. 

Next, the V8 Speed & Resto Shop team installs a Holley LS accessory drive system on the Chevrolet Performance Parts 480 HP LS3 V8.   This system installs the serpentine drive, the water pump, alternator, power steering pump, and air conditioning compressor on the front of the LS3.     The Holley Dominator engine wiring harness is installed before the engine is installed.  

Then, they install a Tanks, Inc. electric fuel pump and tank in the 1969 Corvette to provide the high pressure fuel needed by the Holley Dominator engine management EFI system to properly run.   

We invite you to contact the V8 Speed and Resto Shop anytime at 314.783.8325 for a Corvette LS Swap or any type of LS Swap in a classic or muscle car.   

V8 Speed & Resto Shop

817 S. Main Street

Red Bud,IL 62278

314.783.8325

http://www.v8speedshop.com 

resto@v8speedshop.com  

Take a tour of the V8 Speed & Resto Shop!

https://youtu.be/zQiSQ6Ijo5U 

SUBSCRIBE:  https://goo.gl/RIkdDS 

FACEBOOK PAGE:  https://www.facebook.com/V8TVshow/ 

SHOP FACEBOOK PAGE: https://www.facebook.com/V8SpeedShop/ 



|UPDATED|4/20/2020 11:18:26 AM (AZT)|/UPDATED|


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-Adam Wartell
NCM Lifetime Member #1222
Founder: C3 Vette Registry 
C4 Vette Registry, C6 Vette Registry

My first Vette, now owned by JB79:

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Re: C3 Corvette LS Swap 6 Speed Manual Transmission Swap (2/3)
 4/22/20 12:00am
NorskyLifetime Member
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Twin Lakes, CO - USA

Vette(s):
SOLD - "The Toy" - 1970 Convertible
SOLD - "The Beast" - 1990 ZR-1 (#682)
"BLKBRRD" - 1978 Trans Am, 400ci/225hp, 4 spd, Black w/black interior, Hurst t-tops


Joined: 1/23/2002
Posts: 6885

Sarge - any comments...??? 

Had I not purchased "The Beast" I might have looked into going down this path with "The Toy" to have made it a more trust-worthy road trippin' car.



______________

Jim Olson 

"The Toys"...!!!  Save the Wave!

Where I've been in a Corvette...!!!

Re: C3 Corvette LS Swap 6 Speed Manual Transmission Swap (3/3)
 5/5/20 1:21pm
ateupjoeLifetime Member
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Cleburne, TX - USA

Vette(s):
1978 Stingray - needs a little TLC, bought for wife's 50th Birthday


Joined: 4/10/2010
Posts: 18

I have really been thinking about lots of these items for our 78. Maybe we need a tech talk gathering at the FtW convention so we can hear it from those that have done it first.



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1978 50th BD gift to my bride

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