6.4L Hemi in 1970 Barracuda

Author Topic: 6.4L Hemi in 1970 Barracuda  (Read 6563 times)

Offline 1970GranCoupeConvert

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6.4L Hemi in 1970 Barracuda
« on: April 15, 2015 - 04:53:32 PM »
Hi Cyber Mopar Fans,

Well...I am about to take the plunge into the world of Modern Hemi in a classic ebody.   :money:

I have a restored and stock 1970 Barracuda convertible and I am going to transplant a modern 6.4 Hemi with a NAG1 transmission.  My goal is to use 100 percent stock modern Hemi engine and transmission components (no aftermarket hot rod changes) and to drive the car as a cruiser.
I want to keep the exterior appearance of the car stock and I am aware of the need to modify the following components:
Naturally some advice from guys who have done this swap would be helpful.


I am either:

1).  Buy a low mileage engine and transmission with the various modules and the shifter as a package.
OR
2).  Buy a new MP 6.4L Hemi  production engine and then buy a low mileage NAG1 transmission and the modules and shifter as separate units. 

I am leaning toward option 2.  Yes it is more of a pain in the butt to find those parts however those transmissions are very easy and cheap to find because nobody is using them as swaps and the same goes for the modules.

Has anyone gone either route and would like to give advice and or send some photos or link to build blog?

Does anyone have any of these parts available for sale?

What year transmission and parts should I pick?

What vendor do you recommend I use for the engine/trans harness?

What vendors should I stay away from (offline comments are preferred)?

Here is the stuff I am aware of…

Shifter:
Naturally the shifter will need to be adapted to the existing automatic center console (the 1970 OEM console will need to be elevated to accommodate the increased height of the modern shifter and cut open to accommodate the width of the modern shifter OR I can delete the console completely and just have carpet)

Transmission:
The OEM trans cross member support will need to be redesigned to accommodate the girth of the NAG1 and the lower support fabricated.   Trans cooling lines will need to be plumber as well.

Drive shaft:
Drive shaft will need to be altered.

Fuel system:
A in tank high pressure fuel pump will need to be installed and a new fuel line installed.  I hear guys are running the 99 Corvete fuel filter/regulator and then running a single fuel line to the engine compartment.

Engine compartment:
Radiator and cooling system hoses.  Engine mount.  K Frame will need to be modified to accommodate the oil filter.  My hope is to cut out a chunk of the K Frame where the conflict is with the oil filter and then fabricate a stiffener as needed.  This will only work IF the suspension parts do not attach where I need to cut out parts.

Gas pedal:
Gas pedal will need to be converted to the electronic unit.

Speedometer:
Speedometer will need to be GPS sensed with an electronic servo motor OR the mechanical workings replaced with calibrated needle drive.  What is the best route?  My guess is the speedo mechanism removed and replaced with new.  What vendors can do this?

More stuff I cannot think of right now


1970 Plymouth Barracuda Gran Coupe Convertible
First Car (purchased in October 1985)
Drove it throughout high school and early college (still do)
Full Frame off (K frame off) Rotisserie Restoration completed in 1991
Originally (and still is) a Rally Red, Black top with Charcoal/Silver Interior
340 CID with Holley Pro-Jection 4Di
LA 727 GearVendor  Overdrive
390:1 8 3/4 Rear end
Rally Rims (color matched)




Offline JoeGrapes

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Re: 6.4L Hemi in 1970 Barracuda
« Reply #1 on: April 15, 2015 - 08:25:04 PM »
Could I offer a dumb comment mostly out of ignorance? I can see why some shops are willing to go that route with all the expense and work involved just to say they did it. But if you just want a nice cruiser that runs like a modern car why not modify the motor you have with the usual speed parts plus an aftermarket EFI and an overdrive trans? It sure would be a lot easier and less expensive and you would end up with the same amount of power and be just as drivable. I realize I'm not taking into account the value of the wow factor of a modern motor in an old car. Just my two cents.

Offline dfrazz

  • 1970 Cuda - 1968 Charger
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Re: 6.4L Hemi in 1970 Barracuda
« Reply #2 on: April 15, 2015 - 08:55:55 PM »

1).  Buy a low mileage engine and transmission with the various modules and the shifter as a package.
OR
2).  Buy a new MP 6.4L Hemi  production engine and then buy a low mileage NAG1 transmission and the modules and shifter as separate units. 

I am leaning toward option 2.  Yes it is more of a pain in the butt to find those parts however those transmissions are very easy and cheap to find because nobody is using them as swaps and the same goes for the modules.


I have a NAG1 out of a 2010 SRT Challenger with 3500 miles for sale.  PM me if interested.

Offline glovemeister

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Re: 6.4L Hemi in 1970 Barracuda
« Reply #3 on: April 16, 2015 - 01:13:18 AM »
Why not get a full salvage car and swap in the front kframe from that into your car?
Same with the rear?

An entire car can be had for about the price of an Alterkation setup.

You have everything you need that way as well.
1971 Challenger RT