Overdrive Transmission for my 'cuda?

[dalevt]

So, I got screwed last spring by buying a "rebuilt" 904 transmission for my 'cuda.  It is complete crap, slips like crazy, the thing will only have the torque to do a burnout if it's in reverse, and it makes a terrible whining sound at 60 mph.   

Time for a swap.  I was just going to bite the bullet and have the original 727 rebuilt, but I'd like something with overdrive so I have some top end speed for the interstate, and better fuel economy.  BUT, like everything, this is on a tight budget. 

Can I swap a transmission out of a 2wd Dodge Dakota pickup or something else with an overdrive transmission?  I'm guessing this won't work with my slap stick shifter? 

Please ,
Dale

[Bullitt-]

There is an later model overdrive that will work but the fit is poor requiring major mods to the tunnel & frame.

[mach3107]

Haven't done it yet but there are several subjects where guys are using 518 aka 46rh transmission. I believe from early to mid 90's dodge trucks and vans. These will work on small blocks and I even know a guy who makes adapter plates to go on a big block. I bought a 46rh out of a van. The rh over the re because it's hydraulic, no computer, just a switch for lock up and a switch for over drive. My tranny guy said he will rebuild it for about $1000 including converter. He said it will hold up to the 515 hp because he will build it like he would for a truck only my 73 challenger is lighter and wont pull anything. I think one post shows no modification to the tunnel and you can still use the slap shifter. Hope this helps.

[Cooter]

Sounds like you are NOT the type to deal with modifying the car very much, so an OD isn't gonna be a "Bolt in" deal...Better off buying a gear vendors or a Keisler set up...Course, there goes the budget...

[Cuda54]

A trans shop I know changed bellhosing on a dakota trans with overdrive to fit big blocks. But it will only hold up to a 400hp engine. I have a 727 that was done at this shop in my 72 Cuda with 440-6 with 525hp at the crank and it works great. I have 3.30 gears and at 70mph the tach is at about 2800rpms. Not the best mileage but not to bad if I stay out of the 6 pack. And I am not able to get it to hookup yet. But real muscle cars do not need the brakes to get the tires to smoke! So I would go with a 727 instead of a 904 and change the rear gears.

[burdar]

The problem is the the 500/518 transmissions are a lot wider in the tail shaft area then a 904/727.   The tail shaft in the OD trans will interfere with the x-member in the trans tunnel.  Most people don't want to make the major changes required to fit a Chrysler OD trans in these cars.

[Kapteenikosmos]

If you are willing to go with GM trans you could try the one that Tubbed440 is using (4L80E). Apparently it should fit e-body without butchering the cross member and drive shaft tunnel. There was also some company that sels a mopar conversion bellhousing for that trans.  I am interested in that setup and will probably try it out eventually.

[tactransman]

http://www.cuda-challenger.com/cc/index.php?topic=23678.0

[ChallengerHK]

There is an later model overdrive that will work but the fit is poor requiring major mods to the tunnel & frame.

Didn't Shelbydogg fab a new trans crossmember to address this?

[Bullitt-]

Didn't Shelbydogg fab a new trans crossmember to address this?

It appears so    http://www.cuda-challenger.com/cc/index.php?topic=23678.msg232117#msg232117
 but everything I had read otherwise stated the frame cross-member had to be hacked... 

[ShelbyDogg]

It appears so    http://www.cuda-challenger.com/cc/index.php?topic=23678.msg232117#msg232117
 but everything I had read otherwise stated the frame cross-member had to be hacked...

The only thing that has to be cut off is the rib on the side of the transmission to fit around the trans crossmember.   I removed a 3 inch section.  And a little piece removed for the slap stick linkage to fit.
You will have to make a new bolt on tranny mount to hold it up.

I edited the original post to show the section to cut off the 518 case to make it fit.

You could get a 500 transmission which is like the 904 with an overdrive.   Smaller case, smaller problems.

http://www.cuda-challenger.com/cc/index.php?topic=23678.0

But here are a couple of pics anyway.

[ChallengerHK]

Did you have to fab a mount as well, Rob, or were these changes enough?

[ShelbyDogg]

Did you have to fab a mount as well, Rob, or were these changes enough?

You will have to fab the lower mount.
They show a picture of one below and sell the parts to make it shift itself. You could just put in a switch to save money.

http://www.transmissioncenter.net/SwapInformation.htm

[ShelbyDogg]

Quote from: Cooter on February 18, 2011 - 06:28:21 AM

Sounds like you are NOT the type to deal with modifying the car very much, so an OD isn't gonna be a "Bolt in" deal...Better off buying a gear vendors or a Keisler set up...Course, there goes the budget...



Thanks for the confidence boost.  I'm a mechanical engineer and my dad, best friend, and uncle are mechanics.  We put an LS1 in my 70 Vette a couple years back, I think I can handle this.  They are all GM guys, all I wanted to know was what trans to put in.

It is a smallblock




I don't know what happened to the posts above but maybe the server had a hiccup.  Let me add that those other options are over $3000.  The 518 or 500 trans from the Pick & Pulls were cheap. One 518 cost me $75, with the converter, yoke and lines. The second one I got during their 3 day weekend 1/2 off sale. I got it for $35 with everything above and I had a mini starter bolted on to it.
Make a mount, shorten a spare driveshaft, then you're flying with all Mopar parts.

[tactransman]

Make a mount, shorten a spare driveshaft, then you're flying with all Mopar parts.