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.
|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.|