what transmission to use with new hemi 5.7

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snapetwo

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Ok, so there is litterally hundreds of threads on the net about this. But I am still confused, overwhelmed really..

I ultimately want a manual tranny, so I may decide to hold off on doing anything im about to talk about.

As it sits now, I have both a 904 and a 727. My hemi dart will see highway driving, so I want an over drive. From what I read this will drop that RPM at high speeds.
I have read about OD addons, and even a 518 tranny...but then there is computer verse not computer controled, etc etc.

I am lost.

If I got manualy, its gonna be work as I am gonna try to stuff in a t56.
HOWEVER, if i did decided to stay auto, what would be best?
Take my 727 and get it upgraded (i have read it may need to be beefed up for the hemi), and then add an OD?
Get a 518?
then there is even the 545RFE, which can be controlled by the ecm..helps with throttle kickdown linkage issue.

Any directions or help narrowing this down, would be greatly appreciated.
 
Get a 518 and be done--You can either have it operated by vacuum or a switch on the dash!!!!! Are u going carb or e.f.i that could be a deciding factor in your choice--Steve
 
swift, one of my homies on here always replying to me.

Totally going EFI, no point in going through all this trouble, dealing with all these hurdles, computer, harness, no distributor, etc etc, just to make it a carb.

Think im going to use hotwire auto too, im assuming they can hack that computer to control a tranny if needed (i know they told me that can program the ecm to ignore the tranny)

DO need a little expalining, controlling it on the dash? whats that mean?
Mind you I have never driven a car that had an OD, that I had to control.....if thats how this works.
 
If your going EFi with a Hotwire harness then you might as well stuff the 545rfe in. It involves cutting the floor just the T56 you planned. However it's a 5 speed auto with 2x 2nd gears. One for cruising upto speed and one downshift gear. The 545rfe has 2 overdrives I believe as well.

The 904 and 727 are nice but having the extra gears and modern parts is a bonus.

Then again I've got a T56, so I went that route.

Riddler
 
Ya, right now Im trying to locate both. that 545rfe aint cheap neither, even on car-parts.com.
maybe I just need to put the 727 on it for now, and try to find a t56
 
I bought this 06 model 545RFE that has 32K miles on it for $350 at a semi local truck junkyard. It came out of a 2WD Durango.

Transshop005.jpg
 
Yep have to agree if you have the board and harness go for it although you will have to be creative with the cross member to support the beast!!!! Steve--What I meant was on my buddies daytona when we put the 340 in it he had a 518 built with a solenoid so that he can flip a switch on the dash so it will not shift into overdrive if he does not want to,When he wants overdrive he just turns the switch on!!!! Steve
 
snapetwo said:
will a stock 727 be able to handle a 5.7?
Click to expand...
If you rebuild the 727 it can handle the power and bolt right up to the hemi no problem. That said if youre going to cut the tunnel to install a tranny, way waste money by using an auto o/d (which you don't want) instead of just install a 6 speed manual? There is a thread on here about someone installing a 6 speed manual in their dart (I think it was/is a T56 tranny). I would just pull the TKO 6060 out of a new challenger and have at it.
 
Spoke with Lakewood/Quicktime the other day and was told they can build an adapter for damn near anything. As long as they have a plate for the motor, which they do for a 3g HEMI they can pretty much put any trans behind it. As to the 727 they survive behind 800 hp 2g HEMIS......your 5.7 will be a far cry from that....
 
Guess I'd like to drive the car sometime soon, versus having to wait to save up the few thousand, that it's gonna take to get a junk yard tranny, or even more for a keisler, passon, etc
 
So tell me, whats wrong with an automatic o/d trans?????
 
Oops, that was for 1970duster.
 
You have A-LOT of choices behind the gen III Hemi, the bell-housing is basically the same as an LA motor minus a single bolt at the top.

Automatics:

904 or 727 both can easily built to handle the torque and HP of a Hemi. No modifications to floor pan. Though you do need to shim the trans .060 as the modern Hemi has a different off-set. Bouchillon Performance and many others sell the spacer. Otherwise it is a direct bolt up.

A518 has an overdrive and as others have pointed out requires floor surgery, though not nearly as much as a RFE545. Does NOT require a computer. Can easily be built to handle the torque/HP of a modern Hemi. Like the 727/904 you should shim trans.

RFE 545 Stock Hemi trans. The truck/SUV trans has the speed sensors built into the trans so it is the easiest to retrofit into a muscle car. Hot-Wire can build you a wiring harness to use the truck transmission behind your hemi. Benefits a five speed with two overdrives. Requires SIGNIFICANT tunnel surgery, along with a custom cross member.

Gear Vendors - You can add an over-drive from Gear Vendors to a 727/904 requires virtually no tunnel surgery. (Okay, you might have to dimple the floor in one sport.) Downside? Pricey $2800.00 retail

Manual Transmissions:

A833 is nearly a direct bolt up simply buy an appropriate flywheel and take a die grinder to the input shaft (must shorten it slightly). With all manual transmission switching to a hydraulic throwout bearing is probably recommended as Z-Bar interference with exhaust is likely.

T-5, TKO transmissions, again since it basically has a small block bell housing using one of these transmissions fairly straight forward. The T-5 might be a little on the weak side for a Hemi, but they are cheap and plentiful. Some cutting of the floor is probably in your future.

T-56, 6060 Six speed transmission bell housing are available from Quicktime, be sure to know exactly what your T-56 came out of, as GM t-56 require a different bell-housing than a viper t-56. Either way, major tunnel surgery is in your future, including a custom cross member. Benefit two overdrive gear ratios. Price is dependent upon your ability to score a bitchen' deal on a transmission.

Passon-Performance 5 Speed. If it is ever released this is probably the ideal set up. No cutting of the floor, far stronger than even an 18 spline hemi A833. Only downside is that it is going to sell for $4295.00. That for the transmission and shifter. Bellhousing, flywheel, clutch, etc. Extra. According to what I've read so strong Passon bent the floor of a car in testing, but didn't break the transmission.

Gear vendors, like the autos gear vendors makes an over-drive for the A833, only downside is price, and it does make the trans quite long.

Last but not least you can spend 5K on a trans from Jerico.

Regards,

Joe Dokes
 
4l80e will also fit, just call Lakewood/Quicktime and talk to them about an adapter......
 
I have the 545 in mine and I'm very happy with it. I put a Trans-Go shift kit, and a line pressure adapter ( bumps up the line pressure ) ( both less than $100) and this thing shifts like a bear. Yes there was some tunnel surgery, and had to fab a crossmember, but compared to the costs for some of the other options, It's a good way to go. I have 3:50 gears and at 70mph my motor is revving 2000rpm. Thinking of bumping up to 3:73's
 
I went with the 545RFE. Wasn't $350 ( good find BTW ) but it was 26K miles and was able to get starter, flex plate, TC for about $650. If I had to do this again I would get it from a jeep along with the shifter and ECU. This way I could have an autostick setup.
 
I noticed the nag1 is omitted. I wish I could post the pictures of everything we have. Unfortunately we can't at the moment. The NAG1 is the best transmission to put behind a new hemi. It is exceptionally well built, you can build it to hold a nearly unlimited amount of power. It is geared well.

I know everyone shys away from it because the electronics, but I am telling you we have the electronics worked out. The 545 is JUNK, you can break them with a stock 6.1. Plan on spending $2000 to buy a nag1, converter, and electronics. It will hold 550 wheel horsepower in stock form.
 
Joe Dokes said:
You have A-LOT of choices behind the gen III Hemi, the bell-housing is basically the same as an LA motor minus a single bolt at the top.

Manual Transmissions:


Passon-Performance 5 Speed. If it is ever released this is probably the ideal set up. No cutting of the floor, far stronger than even an 18 spline hemi A833. Only downside is that it is going to sell for $4295.00. That for the transmission and shifter. Bellhousing, flywheel, clutch, etc. Extra. According to what I've read so strong Passon bent the floor of a car in testing, but didn't break the transmission.


Joe Dokes
Click to expand...

It sounds like you ultimately want a manual transmission because of the fun factor so I'd make that your long term goal. In the short term, I'd probably go with the cheapest route to use the 904 or 727 (that you already have) just to get the car on the road ASAP. Then make your choice of trannies and start collecting parts for the manual. I agree, the Passon is not going to be cheap, but it will install with no surgery using a factory bellhousing.
I'm probably going to do the reverse. Factory 833 conversion first (I have all the parts now), followed by a 3G hemi, then an O/D manual of some type. By the time all that happens, I'll probably be too feeble to push a clutch pedal and have to go back to an automatic anyway.
Just my 2 cents.
 
I think your right Kos,
I been researching my arse off, I think right now Im gonna be going with a tko600 from American Powertrain for $2300, then getting a bellhousing from quick time. Looks like the rm-8076 is what I need.
Then im gonna do a hyrdaulic setup, i don't wanna fuss with mechanical linkage..
UNLESS, I come across a smoking deal on something else like a t56.

As far as surgery, i don't mind. I am gonna putting in subframe connectors anyway, so makinga crossmember is nothing, and as far as a floor pan, oh well.
 
I bought a TR6060 out of a wrecked challenger for $900. If you look enough there are deals out there.
 
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