Mopar A833 Manual Transmission Identification and Gear Ratios

There are two basic types of the New Process A-833 transmissions used by Mopar muscle cars. They are easily identified by the length of the tailshaft.

Short tailshaft transmissions are 23 3/16″ inches from where they mount to the bellhousing to the end of the transmission and are found in the smaller A-body and F-body cars.

Long tailshaft transmissions are 27″ inches from where they mount to the bellhousing to the end of the transmission and are found in the mid size and larger B-body, E-body and C-body cars as well as light trucks and vans into the 80’s.

Transmission 1st 2nd 3rd 4th Notes
1964 – 1966 A-body 3.09:1 1.92:1 1.40:1 1:1 Slant Six and Small Block engines. These transmissions had a short tailshaft and used a small 4.35″ input bearing retainer size.
1964 – 1970 B/RB engine 2.66:1 1.91:1 1.39:1 1:1 These transmissions had a long tailshaft with a single forward shifter mounts which is not on the same position as the later 1971-1974 transmissions. This is considered the “close ratio” V8 gearbox.
1966 – 1971 Hemi or 440 Six Pack engine 2.65:1 1.91:1 1.39:1 1:1 These transmissions had a long tailshaft with a single forward shifter mounts and a 1 1/8″ thick 18 spline input shaft. These are the heavy duty A-833 transmissions.
1967 – 1974 A-body 2.66:1 1.91:1 1.39:1 1:1 These transmissions had a short tailshaft are were the standard four speed offered in V8 A-bodies.
1970 only – Challenger T/A or AAR Cuda w/ 340 Six Pack 2.47:1 1.77:1 1.34:1 1:1 These transmissions had a long tailshaft with dual shifter mounts.
1970 – 1974 High Performance 2.44:1 1.91:1 1.34:1 1:1 These transmissions had a long tailshaft with dual shifter mounts.
1975 – 1987 Passenger Car Overdrive 3.09:1 1.67:1 1:1 0.73:1 These transmissions had a short tailshaft and used the large 5.125″ input bearing retainer size.
1975 – 1987 Truck Overdrive 3.09:1 1.67:1 1:1 0.71:1 These transmissions had a long tailshaft with dual shifter mounts and used the large 5.125″ input bearing retainer size.
1981 -1986 Chevy/GM Truck Overdrive 3.09:1 1.67:1 1:1 0.71:1 This A-833 used a 10 spline input shaft and had a bolt pattern specific to the GM A833 bellhousing. General Engines designated this transmission code MY6.


6 comments »

  1. Jim Wolf said,
    August 13, 2011 @ 11:39 am

    Can the smaller input shaft and bearing retainer be replaced with the larger 5.125” 18 spline ? Im having a hard time finding parts for my 78 D100.

  2. Mark Koenig said,
    July 28, 2013 @ 12:39 am

    I have a standard ’67-’74 A-body A833 in my ’66 Barracuda 340. I just picked up a ’75-’87 truck overdrive A833 with the dual shifter mounts. I’d like to switch to this overdrive transmission. Can I switch the car tailshaft onto the truck OD transmission? I’d like to keep my shifter in the same place & use my existing drive shaft. Do I need to do anything else?
    Thanks.

    • Scott said,
      July 28, 2013 @ 1:12 am

      The overdrive main shaft is different than a non-OD main shaft so unfortunately this is not a straight across swap.

    • Gregory said,
      April 1, 2015 @ 2:35 am

      do you still have this transmission

  3. Mark said,
    October 18, 2013 @ 2:00 pm

    I just got A833 from the J/Yard and it has the following numbers . Appreciate relevant info ,thanks.
    C 13157
    C13546
    B 08 B 2983
    C 99538 SS

  4. bob dollenmeyer said,
    April 10, 2015 @ 2:26 am

    i have what was told to me is a new process trans that was removed from a 1970 chevy nova, big block. the input shaft is 10 spline and the output is 27 spline. both the main case and tailshaft are aluminum. the main case is 10 1/8 inches and the tailshaft is 10 12-10 5/8 long. the input and output shafts are both 1 1/8 OD. this is not listed on any of the above listings. it has C15390 embossed on the case and there is a place on the side with the following stamped info; cbf379940(which i am guessing is the serial number on the vehicle it was originally installed in?) with the numbers 14030811 127 1. it has a hurst competition plus shifter on it also and there is no number on the shifter to identify what that shifter was used on! i will get in touch with hurst to see if there is any way to identify on what application the shifter is actually used.
    any help would be greatly appreciated and a value would be helpful also.

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