6.4 Hemi swap into 65 Fury

twostick

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You may want to rethink those 3.91's.

1st gear in a NAG1 is a pretty steep 3.59:1 and 5th is only .083. That 1st gear with 3.91's gives you a starting line ratio of 14:1 and it will feel like it has a granny 1st gear from an NP435. 10:1 is what you usually shoot for in a drag race application and it will feel plenty sporty on the street.

The stock SRT axle ratio is 3.06 and the R/T uses a 2.82. I wouldn't go any steeper than a 3.23. No MDS on an SRT so it might get pretty thirsty at highway speed.

Gear ratio
1 - 3.59
2 - 2.9
3 - 1.41
4 - 1
5 - .083

Kevin
 

Andy Smith

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You may want to rethink those 3.91's.

1st gear in a NAG1 is a pretty steep 3.59:1 and 5th is only .083. That 1st gear with 3.91's gives you a starting line ratio of 14:1 and it will feel like it has a granny 1st gear from an NP435. 10:1 is what you usually shoot for in a drag race application and it will feel plenty sporty on the street.

The stock SRT axle ratio is 3.06 and the R/T uses a 2.82. I wouldn't go any steeper than a 3.23. No MDS on an SRT so it might get pretty thirsty at highway speed.

Gear ratio
1 - 3.59
2 - 2.9
3 - 1.41
4 - 1
5 - .083

Kevin
Thanks for that! This is my 1st round with a Nag1 transmission. The car was already set up with the 3:91 gear so I just left that gear in the car. I DO have a set of 3:23s here that I can pretty easily swap over.
Thanks again. That's some very useful information!!
 

1978 NYB

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You may want to rethink those 3.91's.

1st gear in a NAG1 is a pretty steep 3.59:1 and 5th is only .083. That 1st gear with 3.91's gives you a starting line ratio of 14:1 and it will feel like it has a granny 1st gear from an NP435. 10:1 is what you usually shoot for in a drag race application and it will feel plenty sporty on the street.

The stock SRT axle ratio is 3.06 and the R/T uses a 2.82. I wouldn't go any steeper than a 3.23. No MDS on an SRT so it might get pretty thirsty at highway speed.

Gear ratio
1 - 3.59
2 - 2.9
3 - 1.41
4 - 1
5 - .083

Kevin

I have a 2019 Scat Pack Charger with a 6.4L with a 3.09. And I have a 2019 Redeye Challenger with a 3.09. The Hellcat standard gear is a 2.62. Both of my cars are 8 Speed's.
 

Dsertdog

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Congrats on a job well done. I really like the modern motor swap!
 

1978 NYB

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It has an 8 3/4 rear with 3:91 ratio.

That axle should be able to handle the 6.4L power. You might want to add an adjustable pinion snubber to limit the travel of the pinion end of the 3rd member.

https://www.manciniracing.com/newpr834adpi.html

mancini-racing-adjustable-pinion-snubber-51.gif
 

1978 NYB

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What are you doing for a fuel pump mod?

It needs a lot of volume and PSI to run and a return line.
 

FarCanal

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Finally got it running!! Sounds good! Here's a link to see if the Fury running.


Howdy
I reckon 90% of people on this site would LUURRRV that combination in their car .... lol
Can I see a close up of those exhaust tips please ?
What the hell are they ?
What are they off of ?
Are they big enough ?
Please reply
Big Jim = DownUnder
 

Andy Smith

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Howdy
I reckon 90% of people on this site would LUURRRV that combination in their car .... lol
Can I see a close up of those exhaust tips please ?
What the hell are they ?
What are they off of ?
Are they big enough ?
Please reply
Big Jim = DownUnder
Howdy
I reckon 90% of people on this site would LUURRRV that combination in their car .... lol
Can I see a close up of those exhaust tips please ?
What the hell are they ?
What are they off of ?
Are they big enough ?
Please reply
Big Jim = DownUnder
Howdy
I reckon 90% of people on this site would LUURRRV that combination in their car .... lol
Can I see a close up of those exhaust tips please ?
What the hell are they ?
What are they off of ?
Are they big enough ?
Please reply
Big Jim = DownUnder
Hey Jim ! Those are billit aluminium flame tips. I bought those sometime around 1997 or 1998 from the JC Whitney catalog. Kinda big and Gordy. I know it's time to change them, but right now I'm not working due to the corona virus. When we get back to normal here, I'll switch to a more normal exhaust tip. LOL!!
 

Andy Smith

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Hey Jim ! Those are billit aluminium flame tips. I bought those sometime around 1997 or 1998 from the JC Whitney catalog. Kinda big and Gordy. I know it's time to change them, but right now I'm not working due to the corona virus. When we get back to normal here, I'll switch to a more normal exhaust tip. LOL!!
Howdy
I reckon 90% of people on this site would LUURRRV that combination in their car .... lol
Can I see a close up of those exhaust tips please ?
What the hell are they ?
What are they off of ?
Are they big enough ?
Please reply
Big Jim = DownUnder
Screenshot_20200426-090137_Gallery.jpg
Screenshot_20200426-090137_Gallery.jpg
 

PhoenixThe70Fury

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Hey there! Beautiful fury you got there! I am in the process of looking for a rotted/wrecked dodge pickup or charger with a 5.7 in it and 5 speed auto to swap into my 70 Fury III four door. I got a couple questions. Did you wire the stock fury ignition switch into the chargers wiring or how was this accomplished? Is there a way that you know of that I can keep my stock colum shifter (I have a bench seat and intend to keep it that way) or do I need that mid section shifter? I got a whole lot more questions for ya!
 

furious70

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12-13 years ago I saw a Challenger with a truck engine/trans swapped in with stock slap stick shifter. They got it to control P,R,N,D. You could not control fwd gears with the shifter. The truck trans is bigger and has bad gear splits but is designed to work with a column shifter mechanism.
I'm going to do turbo 5.7/nag1 someday to replace the turbo 383, I've collected the stock shifter from a 300c, trans ecu, etc along with the nag1.
Holley is now making a ton of hemi and nag1 conversion parts, you almost need to check their site weekly.
 

Andy Smith

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Hey there! Beautiful fury you got there! I am in the process of looking for a rotted/wrecked dodge pickup or charger with a 5.7 in it and 5 speed auto to swap into my 70 Fury III four door. I got a couple questions. Did you wire the stock fury ignition switch into the chargers wiring or how was this accomplished? Is there a way that you know of that I can keep my stock colum shifter (I have a bench seat and intend to keep it that way) or do I need that mid section shifter? I got a whole lot more questions for ya!
 

Andy Smith

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I did wire the factory ignition switch to the Hemi harness. I bought the harness from Hotwireauto.com, and he had everything labeled on how to wire it up.
The shifter that I HAD to use was from an 07 challenger. It needed to be programmed to work with the Nag1 transmission. If you choose to adapt a 727 transmision to your Hemi, then you can use your factory shifter. The Nag1 is a way different transmission. I dont think you would be able to use your column shifter on the electric shift transmission.
 

flj

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Thanks for that! This is my 1st round with a Nag1 transmission. The car was already set up with the 3:91 gear so I just left that gear in the car. I DO have a set of 3:23s here that I can pretty easily swap over.
Thanks again. That's some very useful information!!

Hi Awesome work:
I am getting on this thread late but hopefully not too late.

I have just started a 2009 6.1L/NAG1 install in a 1967 Polara 500 convertible. Reading your write up is inspiring but also frightening. Nothing ventured, nothing gained!!

Where did you get your drive shaft fabricated?

Also with the NAG1 transmission, the final drive ratio of 0.83:1 means that you need a really low rear end gear ratio around 3.0:1 or lower as previously mentioned. I am looking at a 2.94:1 rear end or even one of the dreaded 2.76:1 rear ends. I am not sure that you can get a sure grip for those rear end gears which means only half the fun...pardon the pun.

Can you get a sure grip installed on a 2.786:1 or a 2.94:1 8 3/4" rear end?

Inspiring work.
 

furious70

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yes - there's nothing about the ring and pinion that affects being able to install a sure grip - it was just really rare for anyone to ever order a 2.76/3 SG back then.
 
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