6.4 Hemi swap into 65 Fury

furious70

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though 3.23 * .83 = 2.69. I know the modern engines actually stroll along with less of a final drive ratio that that but you wouldn't be in bad shape with a 3.23. The 'performance' gear for the modern hemi cars is 3.09 I think? 2.62 for regular 5.7's?
 

Andy Smith

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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.
I'm pretty sure you can get a sure grip, or posi unit for the 2:94. Im currently running a 3:23 gear set, and have No issues or problems.
The driveshaft was fabricated at Nassau Driveshaft in Merrick, Long Island
Www.nassaudriveshaft.com .
Sounds like a real cool build! I love those Polaras!! Post up some pics as you make progress.
 

67Monaco

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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.

I think you could but you'd have to scavenge the parts out of an old (2000's) police Charger. They were all column shift. Now, adapting that in to a C-body? Who knows.
 

flj

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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.
I will get hold of Dr. Diff and see what he recommends for the rear ends I have. Thank you.
 

RGORHAM29

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


just catching up on this thread. Beautiful car. Love the convertible 65 fury. Really like the heart transplant too. Wondered if anyone had tried this in the fury. Now I know. Good luck!
 

Jack-Stand

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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.

I'm sure the purists are going to have a heyday, but have you considered a different axle? In my '66 Monaco build I swapped the axle to a ford 8.8 due to strength, availability, and also price. Around here you can pick up a junk yard pull-out for $150-200, and if you pull one out of a late-90's explorer, it'll have LSD and disc brakes. The explorer axle is slightly narrower, so you'd have to run a C-clip eliminator to widen it out a bit (planned for mine), but you get a lot of perks for not much money. Only thing with this is that you'd have to regear it (3.08:1 is lowest available), and you'd have to adapt the driveshaft to the 8.8 flange. Other than that, it's a matter of cutting the spring perches off and flipping/welding them to the top of the axle (spring-under vs spring-over). Since you're doing a modern engine swap, I assume you're not concerned with a numbers matching axle.
 

Andy Smith

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I almost went the Explorer 8.8 route. The
8 3/4 is strong enough for the amount of power on the streets. The idea of a strong rear, set up with disk, AND some came standard with a 3:73 gear. Its a no brainer to do the swap if you need to build a rear
 

Jack-Stand

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I almost went the Explorer 8.8 route. The
8 3/4 is strong enough for the amount of power on the streets. The idea of a strong rear, set up with disk, AND some came standard with a 3:73 gear. Its a no brainer to do the swap if you need to build a rear
Exactly, it's a turnkey axle. My 92' XJ is running an 8.8, and it's taken a beating. You can find them stock with 4.10's and LSD, but you've got to hunt at the yards for a while, and if you find one, you'd better grab it that day.
 

savoy64

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you dont have to be stuck with only a nag-1 or a 727 on the 5.7 hemi----a nice 518 will fit right in place---need only to elongate one bolt hole in the flex plate too....the column shifter will work as well.....
 

70bigblockdodge

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you dont have to be stuck with only a nag-1 or a 727 on the 5.7 hemi----a nice 518 will fit right in place---need only to elongate one bolt hole in the flex plate too....the column shifter will work as well.....
Why work that hard to put a terrible transmission in the car?
NAG or a 545 will run squares around that bastardized 727.
 

Andy Smith

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you dont have to be stuck with only a nag-1 or a 727 on the 5.7 hemi----a nice 518 will fit right in place---need only to elongate one bolt hole in the flex plate too....the column shifter will work as well.....
you dont have to be stuck with only a nag-1 or a 727 on the 5.7 hemi----a nice 518 will fit right in place---need only to elongate one bolt hole in the flex plate too....the column shifter will work as well.....
You are right . The 518 will be the easiest fit into the transmission tunnel. It really is worth the extra work to open up the tunnel to fit that Nag1 in there. Im still getting used to the auto stick feature. It's a blast to drive!!
 

Andy Smith

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I would never mess with a 545 or 645. Big and bad gear splits
I have a 46re behind a fuel injected 408 stroker in my Lebaron wagon. That trans kicks ass

Screenshot_2017-05-25-15-26-01.png
 

savoy64

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518/618 built to take the punishment of a cummins motor------lets see if someone ever puts a nag1 behind a cummins or even a 426 light weight race car------and those are handled mostly by built 904,s and power glides.........727 one of the top transmissions ever made-----20 car companies paid royalties to chrysler to use parts of it --including chevrolet--ford--mercedes......
 

Andy Smith

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518/618 built to take the punishment of a cummins motor------lets see if someone ever puts a nag1 behind a cummins or even a 426 light weight race car------and those are handled mostly by built 904,s and power glides.........727 one of the top transmissions ever made-----20 car companies paid royalties to chrysler to use parts of it --including chevrolet--ford--mercedes......
I never knocked any of those transmissions. All great transmissions. You can try putting the nag1 behind a Cummins. I'll stick with the set up in my car. Its a street car. Im not using it on the track.
 

Convertible300L

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Fantastic project, had a great time reading about this.

Have you got it driving?

Any insights on chassis flex given its a convertible?

The 413 in my convertible 300L needs a rebuild and I’m thinking about stroking it with a 4.5 inch crank... but worried about twisting the chassis.

Anyone on here put a 500+ ci motor (or modern hemi) in a convertible c-body?
 

Andy Smith

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It runs and drives really well. The frame rails all need to be tied together to strengthen them up. The car won't hook like its at the race track, so I'm not really too worried about twisting the frame.
I'll be taking the car for a tune on the 6.4.in the next week or so. Trying to squeeze another 40 or so HP out of it. Also turning off the MDS . Then, I will definately look into stiffening that frame up !
 
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