Hemi Swap: Transmission choices for Gen III 392 Hemi

[Chryco Psycho]

Start a new thread in the new members section !

[kawahonda]

I have to admit the 8 speed in my truck is pretty darn impressive. It's the best automatic I've driven by far.

Agreed. The new 8-speed that Chrysler uses is one of the best transmissions they've ever done.

[Hemi1632]

I have to admit the 8 speed in my truck is pretty darn impressive. It's the best automatic I've driven by far.

Agreed. The new 8-speed that Chrysler uses is one of the best transmissions they've ever done.

Yes but getting the new 8 speed to work in an E body is difficult. Especially if you don't want to use the gear selector that it comes with

[392 Cuda]

@Hemi1632 , how did the A41 work out for you?

[Hemi1632]

@392 Cuda The installation of the A41 went great. I started with an 05 5.7 with a 545. I was told that it would bolt right in without having to do any cutting of sheet metal that's why I decided to do the swap, but that is not true. I then acquired a 12 5.7 with a nag1 hoping that it would fit. After taking out the 05 and installing the 12 I found out that it wouldn't fit either. Quite a bit of time went by so I offered to pay a friend of mine to make a new tunnel for me so the trans would fit. My friend asked me if I had considered putting an A41 in the car? When I looked into it I was sold. Everything bolts in, no cutting of hammering. They make the drive shaft for you, the original shift linkage is used, they even make a plate for the slap stick that looks original except that instead of 1,2,D it is 1,2,3,D because the A41 is a 4 speed. Everything is modern but it looks original. Another reason I chose the A41 was that I think that between the labor and everything I would have had to buy to get the nag1 to work the cost would have been about the same.

[Hemi1632]

@392 Cuda  have you decided on a trans yet?

[Brads70]

I've had the A41 kit behind my 451 stroker for 8 years I think it is now. Driven down to Carlisle a few times ( 7 1/2 hours each way) . It's been great no regrets.  Love the 3.06 first gear ratio over the 518's 2.45 gear ratio 

[392 Cuda]

@Hemi1632 , apologies for the late reply. I didn't see a notification for your post.

I am about to pull the trigger on an 8HP70.

It seems like Russell Drake from Sound German Automotive has figured out a controller solution. He recorded the data from a modern car and has a harness read it back to the transmission controller to let it work. You just need a factory (boneyard) shifter to enable it.

US Car Tool now makes a transmission tunnel kit and cross-member for the HP70. Lots of cutting and welding, but my car is far from original anyway.

Looks like I'll be learning to weld, and may have a story for the group soon.

[Chryco Psycho]

It will be interesting to follow this swap !!

[Hemi1632]

@392cuda this sounds good. I can't wait to see updates! In my opinion the 8 speed is on a different level. I couldn't see cutting up the tunnel for a 5 speed over the 4 speed A41 that bolts right in. But an 8 speed? I may have cut it up! I am also looking forward to seeing how you incorporate the shifter. That is the other thing that was holding me back. Are you going to build a custom center council? Are you going to use the interior out of a modern challenger? Or are you still trying to figure it out?

[392 Cuda]

@Hemi1632 I haven't figured out what to do with the console yet. I had actually just mocked up my plate for the original console to hold the power windows/locks and cup holders

The new challenger console is nice, but would take some fabricating to get rid of the controls (maybe drop in a screen to control a carberry pi) and front section that clips into the dash, and might not look quite right overall. The trans hump will be huge after the transplant, but perhaps the stock console can be modified to fit, or a new base can be fabricated to make it look close enough. I figure I can screw with that later. I may just pick up a console at the yard when I get the shifter, and see what I'm working with when the main project is complete.

I have seen a few people on different groups say they can cut some of the bottom of the seats off to make them fit, but I'm not 100% sold on the look of the modern interior. Currently, my car looks stock until you pop the hood.

[Hemi1632]

@392 Cuda It sounds like you have quite a few decisions to make! I look forward to see what direction that you go. I am going with power windows also. I went with Nu-relics, I will let you know how it went after I get them done.

[392 Cuda]

@Hemi1632 , The power windows are the best modernization ever! First thing I do when i get in the car is roll both windows down.

Alan gave me an extremely helpful tip: There are 2 positions for windows in the door. The electric life kit I used gets mounted in the top position, not the position my manual regulators were mounted in.

The electric life kit works pretty well... I've never seen windows roll up/down that fast. It took some bending and a handful of washers as spacers to get them to fit right  (interfered with the stock door lock mechanism - check with windows up and down), and lots of grease for the tracks, but it's a great fit now. The operation was very clunky until the door panels were on to guide the windows.

I also used a relay box from DEI to allow one-touch up/down for both front windows. I hid the box and huge bundle of wires it requires under the console.

[Hemi1632]

@392 Cuda a one touch up and down and drink holders are pretty cool. I look forward to seeing updates as you progress.

[392 Cuda]

I might just use this... have to see what fits after I swap the tranny.