LA 360/904 torque converter/ flex plate combo

Transmission and Drivetrain Tech

  1. 72moparswinger

    72moparswinger Well-Known Member

    Messages:
    175
    Likes Received:
    21
    Joined:
    Jan 3, 2012
    Location:
    Cameron Park CA
    Local Time:
    6:47 AM
    Hey all, I am going to be redoing my 72 date code LA360 hooked up to my 904. My concern is getting the combo correct as the external balance issue I see a lot of.

    I am looking at buying the following converter from Hughes. The 27-25, per the specs on Jegs, it shows the 360 application for 360s of various years including the Cuda and 75 dart swinger and Duster. The 2500 stall is perfect for my cam shaft.

    Hughes Performance 27-25: Street Master Torque Converter 1968 and Newer Mopar A904 (TF6) 6 & 8 Cylinder | JEGS

    I also ordered already the B&M 10239 flex plate. Which I hope will work with this converter to provide smooth operation

    I just want to confirm this choice or see your choices for this particular engine and trans combo.

    Thanks in advance
     
  2. Ahoey

    Ahoey Well-Known Member

    Messages:
    1,465
    Likes Received:
    2051
    Joined:
    Apr 6, 2020
    Location:
    Winnipeg Manitoba
    Local Time:
    6:47 AM
    Can’t remember part #s but when I bought my b+m hole shoot for my 74 360 727 combo the converter was made to fit all engines external and internal the flex plate had the counter weight on it. Recently bought a forged steel rotating assembly from scat cranks with internal balance took flex plate to machine shop and had them machine counter off. No problems to date every runs nice and smooth.
     
  3. Ahoey

    Ahoey Well-Known Member

    Messages:
    1,465
    Likes Received:
    2051
    Joined:
    Apr 6, 2020
    Location:
    Winnipeg Manitoba
    Local Time:
    6:47 AM
    I don’t think Chrysler built a 360 with internally balanced crank look at harmonic balancer if it has the counter weight in it its external balance your stock converter should have a weight on it as well.
     
  4. 72moparswinger

    72moparswinger Well-Known Member

    Messages:
    175
    Likes Received:
    21
    Joined:
    Jan 3, 2012
    Location:
    Cameron Park CA
    Local Time:
    6:47 AM

    Oh it has the weight in the front on the harmonic. I just worry about torque converter choice. Everywhere I look online no converters state “neutral balanced” which is what I need to find. This 27-25 shows 360 applications per jegs but can’t find any info anywhere else. A lot of people when I did digging on FABO had issues with different converters. I didn’t see anyone state anything about this Hughes though. TCI shows something but I see terrible reviews. B&M don’t make anything for a 904 from what I found, otherwise I’d get a B&M
     
  5. Ahoey

    Ahoey Well-Known Member

    Messages:
    1,465
    Likes Received:
    2051
    Joined:
    Apr 6, 2020
    Location:
    Winnipeg Manitoba
    Local Time:
    6:47 AM
    What’s the reasoning for the 904. I have the 727 with the large clutch PACs double wrap bands and a shift kit abused the shit out of it never had any problems change oil and filter often and put your foot in it.
     
  6. abodyjoe

    abodyjoe Well-Known Member

    Messages:
    21,622
    Likes Received:
    7387
    Joined:
    May 22, 2004
    Location:
    Berlin,N.J. 08009
    Local Time:
    7:47 AM
    727 is great if you want to go slow.. other wise run a 904.. :)
     
    • Agree Agree x 1
    • George Jets

      George Jets 1967 Dart 2 Door FABO Gold Member

      Messages:
      4,469
      Likes Received:
      6075
      Joined:
      Jan 18, 2019
      Location:
      Farmington MN
      Local Time:
      6:47 AM
      Yes the 10239 Flex Plate is for the 360 external balanced engine, with the 904 and it's neutral balance converter.

      Screenshot_20210411-105610_Chrome.jpg

      Screenshot_20210411-105603_Chrome.jpg

      ____________

      The #10236 is the flex plate for 360s and neutral balance 727s.

      Screenshot_20210411-105027_Chrome.jpg
       
    • Ahoey

      Ahoey Well-Known Member

      Messages:
      1,465
      Likes Received:
      2051
      Joined:
      Apr 6, 2020
      Location:
      Winnipeg Manitoba
      Local Time:
      6:47 AM
      Well over the years my need for speed has diminished greatly. It’s what the car came with so if it ain’t broke don’t fix it
       
    • 72Dart6pack

      72Dart6pack Harder Better Faster Stronger.

      Messages:
      4,340
      Likes Received:
      4484
      Joined:
      Feb 1, 2016
      Location:
      Roseville Michigan
      Local Time:
      7:47 AM
      I have a 904 behind a 408. Same converter. A stock 318 flex plate is fine. $15 Mancini. Unless you need some high end flex plate?

      20201125_162453.jpg

      20201125_161813.jpg
       
    • George Jets

      George Jets 1967 Dart 2 Door FABO Gold Member

      Messages:
      4,469
      Likes Received:
      6075
      Joined:
      Jan 18, 2019
      Location:
      Farmington MN
      Local Time:
      6:47 AM
      Is your 408 an internal balanced crankshaft? Stroked 360 to 408 with new crank? 360s were external balanced from the factory. Just Checkin' . . .

      904 with factory flex plate and neutral balance converter is for mating up to a neutral balance engine.
       
    • 72Dart6pack

      72Dart6pack Harder Better Faster Stronger.

      Messages:
      4,340
      Likes Received:
      4484
      Joined:
      Feb 1, 2016
      Location:
      Roseville Michigan
      Local Time:
      7:47 AM
      Internal balanced 408 with a new crank. Neutral balanced harmonic. Neutral balanced Torque converter. Bam. Easy pezey. :)
       
    • 72moparswinger

      72moparswinger Well-Known Member

      Messages:
      175
      Likes Received:
      21
      Joined:
      Jan 3, 2012
      Location:
      Cameron Park CA
      Local Time:
      6:47 AM
      I have an external balance 360 thus requiring the B&M plate. I’d have to weight the converter if I don’t run the plate.

      my current converter with the 360 before it broke down has a weight on it but I never liked the idea of it and I think it still had a slight shimmy in the tunnel while maintaining speed. Never had an issue at idle or acceleration or deceleration. Just the maintaining speed part with part throttle.
       
    • 72Dart6pack

      72Dart6pack Harder Better Faster Stronger.

      Messages:
      4,340
      Likes Received:
      4484
      Joined:
      Feb 1, 2016
      Location:
      Roseville Michigan
      Local Time:
      7:47 AM
      I'll take a good 904 any day. Not that 727 are bad. Just my choice. And it's going behind a 408.
       
    1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
      By continuing to use this site, you are consenting to our use of cookies.