70 Cuda Transmission and Diff help needed

Author Topic: 70 Cuda Transmission and Diff help needed  (Read 805 times)

Offline longgone

  • Jr. Member
  • **
  • Posts: 184
70 Cuda Transmission and Diff help needed
« on: August 23, 2007 - 09:38:03 AM »
Just got my 70 cuda I bought sight unseen today from the shipping company.  The car is a little more than I expected from a performance standpoint.  I knew it was a 440-6 pack but I didn't know it was setup for 1/8 mile runs to the extent it is.  I'm wanting a nice cruiser and car I can drive around the state to various car shows.

It has a very low rear end, something way beyond 373 or 411 as I have owned cars with both and this is much more extreme.
Also, it has a manual valve body in the transmission (727) and the shift action is reversed.  It has the stock shifter but you have to start out in D then manually shift to 2 and then 1 (1,2,3 in reality).  It also has a 2500 stall in it.
Don't get me wrong it is a screaming machine but I don't think I could take it on the interstate and go anywhere.

So the help I'm begging my new C-C family here for is:

1. Where is the best place to get the rear end parts needed (summit, jegs)?  What ratio do you recommend?
2. Same question for whatever I need to turn the transmission back to normal operation.
3. Anything else I should consider or I'm not thinking of?

I want a nice cruiser that I can drive around that has some good get up and go but nothing quite as extreme as this.  I'd like to be able to go 70 on the interstate.  I've got a good mechanic buddy who I can get to help me do the work but I wanted to get your thoughts before I called him and got things in motion.

Thanks,
Blueglow








Offline 6packCuda

  • Sr. Member
  • ****
  • Posts: 1932
  • Eagle, NE... Member since 11/17/06
Re: 70 Cuda Transmission and Diff help needed
« Reply #1 on: August 23, 2007 - 09:46:38 AM »
If you're planning on a lot of interstate driving, I would go with something like a 3.23 rear gear ratio. I don't know much about trannys, but I would say you could just purchase a regular stock style valve body for it and that should put your shift pattern back to normal. And, a 2500 rpm stall sounds fine, maybe even a little mild for street use. Summit has everything you would need.
Dave

Offline 1BADFISH™

  • Resident
  • *****
  • Posts: 2805
Re: 70 Cuda Transmission and Diff help needed
« Reply #2 on: August 23, 2007 - 10:32:19 AM »
 :useless:


Lets see a pic of your new car. As far as rear end, I agree with 3:23's.  There's a guy on Moparts who goes by Dr. Diff, he's really good to deal with, maybe try contacting him.

Dave
Charlottetown, PE
2014 GMC Sierra Crew Cab White Diamond edition.
1970 Dodge Challenger 340-6 4spd.
*Member Since* Oct 11, 2005

Offline tactransman

  • Sr. Resident
  • ******
  • Posts: 5401
  • 1973 Challenger- Member here since April 14, 2006
Re: 70 Cuda Transmission and Diff help needed
« Reply #3 on: August 23, 2007 - 01:39:24 PM »
You need to know if the governor has been eliminated or modified to be able to convert it back to automatic shift and what else has been done to the tranny.
Terry-tactransman 
Torqueflite/Automatic Transmission Specialist
Union, Mo.
Give a man a fish and he eats for a day,teach him to fish and he eats for a lifetime.