Best Swap Transmission?

which trans works best for you

  • 904/727 w/GV

  • Nag-1

  • 46RH/RE

  • 8HP70

Results are only viewable after voting.
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Mr onetwo

Mr onetwo

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Good morning to all,
I am gathering parts to swap a 2012 5.7 Ram Hemi into my 1970 C-body Fury.I am here asking this question because far and away this forum has the most activity of any forum.I am asking those who have direct experience with an automatic transmission in their car.First, I am not going to put a GM or Silverstar transmission in my car, period.The 4 choices I have come up with are:
1- the 904 in the car built for 450HP with a Gear-Vendors OD unit
2- a NAG-1 5 speed from a car (police version has column shift)
3- a 46RH from a 2wd pre OBD2 truck (46RE also depending on control options)
4- my first choice...A 8hp70 2014 and up from a car
I am not afraid of the electronic transmissions as Sound German has them solved, just expensive. The 904 w/ GV is probably the easiest and cheapest with no body mods needed.
This is strictly about how well each transmission operates/drives...not fitment.The Fury is a cruiser...mostly secondary roads, very little interstate driving.
Any and all opinions from people with hands on experience is much appreciated! Thanks
 
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My only real world experience with an OD trans in a swap is the truck 545RFE. Works great in that application, but, would require lots of surgery for a car. I was digging around a little over on E Bodies and saw that someone was using the 8 speed with no cutting. Just a little massaging of metal in the tunnel and taking off some casting lugs on trans. I think with the bigger car the 8 speed would be killer!
 
Just did a Challenger and used a 2003 5.7 Hemi , 727 with 323 gears. 3500 stall works great and a handful on acceleration. There was a reason for the converter on hold back at a red light after hitting the throttle and leaving off . We had a 2400 in it . It was also a pig. . No Good, 3000 could have worked but had a 3500 in stock.
 
Depending on the rear gear ratio and your statement of very little interstate driving,sounds like the 904 without a overdrive should do the job.I researched the cost of a Gear Vendor set up for my old truck and when all is said and done you can have $4K invested.Will you be using the Mopar Performance engine controller/wiring harness ?
 
Well, I’ve never done the swap so I don’t have any real experience with any of them, BUT when the time comes that I do a Hemi swap, the only three transmissions I’m considering are the TR-6060, T-56 Magnum and the 8HP70/90.
 
My first choice would be the modern 8 speed automatic. If you're going this far, and keeping the car for awhile, may as well go all in. Good acceleration in the lower gears, almost imperceptible shifts, and good cruising gears. Sound German has you covered, ask for his recommendation.

It's big, but your C-body has a pretty big tunnel. I've seen used ones going for less than $1000 from wrecked Challengers/Chargers. You don't need the Hellcat version.
 
There are at least a dozen on Ebay for $400 to $800 shipped. A tid bit I picked up yesterday is that a car transmission can't be used on a truck block.I'm not sure if that is accurate...any body know for sure?
 
Darter6 said:
Depending on the rear gear ratio and your statement of very little interstate driving,sounds like the 904 without a overdrive should do the job.I researched the cost of a Gear Vendor set up for my old truck and when all is said and done you can have $4K invested.Will you be using the Mopar Performance engine controller/wiring harness ?
Click to expand...
The GV is not cheep for sure.I could do the engine this year and the trans next year but I think not. Sublime(DIYHemi) is developing the harness to do my 2012 truck engine so I will wait for them I think. The kit from Sound German for the 8HP70 is well proven.
 
Mr onetwo said:
Good morning to all,
I am gathering parts to swap a 2012 5.7 Ram Hemi into my 1970 C-body Fury.I am here asking this question because far and away this forum has the most activity of any forum.I am asking those who have direct experience with an automatic transmission in their car.First, I am not going to put a GM or Silverstar transmission in my car, period.The 4 choices I have come up with are:
1- the 904 in the car built for 450HP with a Gear-Vendors OD unit
2- a NAG-1 5 speed from a car (police version has column shift)
3- a 46RH from a 2wd pre OBD2 truck (46RE also depending on control options)
4- my first choice...A 8hp70 2014 and up from a car
I am not afraid of the electronic transmissions as Sound German has them solved, just expensive. The 904 w/ GV is probably the easiest and cheapest with no body mods needed.
This is strictly about how well each transmission operates/drives...not fitment.The Fury is a cruiser...mostly secondary roads, very little interstate driving.
Any and all opinions from people with hands on experience is much appreciated! Thanks
Click to expand...
Sounds like you need to make some decisions on your end goal for the car before you make a decision on a transmission. If you won't ever take it on the interstate, then why do you even need an overdrive transmission. You also need to decide on your budget. 904 will be the cheapest, but maybe not the easiest. You will also have to figure out how to handle the kickdown linkage. If you are going to use a factory ECM, why not use one that will control the electronic trans also? If you choose to use the 8 speed, I believe you have to use the factory shifter from whatever it came out of. That can be a big turnoff for some.
 
Good points. The 8 speed with the Hemi is a dream to drive everywhere.I have that combo in my truck with a 3.21 rear gear.The TCM on the 8 speed is built into the transmission...nothing separate.My car does not have buckets or a console so I will use the rotary knob from a truck since you can make it pretty much disappear.It is controlled by a tone ring sensor setup on the output coupler on the 8 speed. Using the 904 doesn't make much sense the more I think about it.There is an 8HP70 in Connecticut right now for $715 with 20,000 miles on it...pretty cheap.
 
Well, that was easy. I just pulled the trigger on a truck 8 speed with 78,400 miles for $625 shipped on Ebay.Up here that transmission is $1200 to $1500 with twice the mileage.I'm happy!
 
Mr onetwo said:
Well, that was easy. I just pulled the trigger on a truck 8 speed with 78,400 miles for $625 shipped on Ebay.Up here that transmission is $1200 to $1500 with twice the mileage.I'm happy!
Click to expand...

I was just reading an article on Mopar transmissions and saw a picture of a truck 8HP70 and it had some kind of large cooler build into the side of the trans. The same article showed a car 8HP70 and it didn't have the same cooler. Not saying the cooler can't be removed, but thought maybe you should be aware.

www.holley.com

Everything You Need To Know About Chrysler's Late-Model Automatic Transmissions

Chrysler guys, it's time to look past the tried-and-true 727s and 904s. It's time to look at the late-model automatics to see the benefits they can provide you, both from a performance and drivability standpoint.
www.holley.com www.holley.com

Car:

8hp70_01.jpg


Truck:

8hp70_truck_01.jpg
 
That is the thermal unit...1500 truck only. Can be removed and the ports threaded for ORB style fittings.
 
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