Roadrunner with Richmond 6 Speed Transmission

Print Friendly, PDF & Email

A good friend of my father’s has a modified Roadrunner with a 440.  For performance and improved gas mileage he has a Richmond six speed (ROD).  He has had it for awhile but it is failing and needs a rebuild.  He has contacted them but they do not respond and none of big parts suppliers sell the ROD anymore.

Knowing that the people on this site have extensive knowledge and American Muscle in not my strength I was hoping someone here may have suggestions regarding options to have the transmission rebuilt or other available transmissions to keep this ride tearing up the street.




harry p.

Share Button


  1. thanks for the comments everyone, the roadrunner’s owner has modified it and it has over 500 ftlbs at the wheels, the ROD has worked well for years but after enough hard runs it is not performing right. he is likely going to go with the tremec but he liked the ROD because it was really a 5 speed with 1 OD as opposed to a 4sp with 2 OD’s. the ratios were closer in the ROD and first is 3.28 instead of 2.8(something) in the tremec.

  2. from what I have read the ROD is good for 450 ft-lb. Should be fine for a stock-ish 440 cruising on street tires (hard to break stuff when you don’t have traction). If the motor is turned up or if the owner plans on any dragstrip useage then it may be wise to look at a beefier trans, hard to say given the limited information.
    I still think your best bet is to post up on that hotrodders forum, be sure to give plenty of details about the car (engine specs, rear gears, etc…), intended use, and budget limitations (or lack thereof).

  3. Assuming the trans is already in the car? If so, most reputable transmission rebuilders should be able to overhaul it for him. If not then it becomes a bit more complicated, but not too bad (correct bellhousing, flywheel, etc…). Unfortunately I don’t work on transmissions but I have a friend that is very experienced, makes it easy for me anyhow. Don’t have much info to go on here but you could always have the owner ask some questions at (they have a transmission subforum)
    I’m sure they can get him taken care of.

    • Hi Bob,

      One factor that should be taken into account when considering a retrofit of a modern OD transmission (whether manual or automatic) into an old muscle car is the unit’s capacity to handle the torque produced by those old V-8s. Many of the modern transmissions – at least, in OE (“new car”) spec – were not made to handle more than 400 or so ft.-lbs. of torque (several cannot cope with even that much). They will physically bolt up (or can be made to bolt up) but will often fail pretty quickly because of internals not designed to deal with 400-plus cubic inch V-8s that make in excess of 400 (let alone 500-600) ft. lbs. of torque.

      The aftermarket units are – usually – rated to handle the torque of those old big blocks, but check to be sure!

  4. eric,
    thanks for the info, his was modified and dyno’ed at 520 so this would be more than capable.

    i also read up on this transmission on the site and it says it is a “double overdrive”, the ROD has only 1 OD. What is the functional difference between them?

    • You bet!

      IIRC, the “double overdrive” means the top two gears are overdrive gears, with 1-4 being for acceleration and the top two for cutting cruise RPM to a fast idle.

      These OD trannies transform a classic muscle car; make it much more “anywhere drivable.” My ’76 TA, for instance. With a 3.90 ring and pinion in the pumpkin, it was a very frustrating car to drive on the highway. I had to keep it around 60 MPH – and even then, the engine would be really working – 3,300 RPM at that speed.

      But with the OD tranny, my cruise RPM at 70-plus is around 2,000 RPM now…

  5. Hi Harry,

    Love the car! Petty Blue is the right color for a Road Runner!

    On the transmission: From what I gather, most guys who are retrofitting modern overdrive manuals into old muscle cars are going with the Tremec six s-peed. Here’s the PDF/product literature:

    For that big block Mopar, they will probably recommend the T56 Magnum, which is rated for 700 ft.-lbs. of torque.


Please enter your comment!
Please enter your name here