a bit of google magic....
http://www.motivegear.com/tech_info/tra ... guide.html
New Process A833
4-speed transmission, with all forward speeds synchronized. Manufactured in both direct drive and overdrive models. 10 Bolt shift cover mounted on left side of transmission case. Early models had iron cases and late model cases are aluminum. Case length measures 10 5/8 . Used in Chrysler passenger cars 1964-80, Dodge trucks 1976-85, and 1981-86 General Motors trucks. GM models may be identified as RPO code MY6 Produced in 2 and 4 wheel drive versions.
New Process 435
Top loaded heavy-duty 4-speed transmission with cast iron case and extension housing and aluminum shift tower. 2nd through 4th gears are synchronized with 1st and reverse using non synchronized sliding gear. Found in 1963-85 Dodge trucks, 1964085 Ford pickup trucks and stripped chassis, 1964 to 72 GM trucks, and International Harvester and Navistar trucks from 1964-85. produced in both 2 and 4 wheel drive versions.