Two automatic and seven manual transmissions were available during the 1960s and 1970s:

• A-904 automatic transmission
• A-727 automatic transmission
• A-833 4-speed manual transmission
• A-745 3-speed manual transmission (1961-1971 HD applications)
• A-903 3-speed manual transmission (1960-1972 with slant sixes)
• A-230 3-speed manual transmission (1973+  slant sixes)
• A-250 3-speed manual transmission (1973+ with trucks & vans)
• A-390 3-speed manual transmission (1975+)
• T-87 3-speed manual transmission (late 50s - early 60s - Borg Warner)

Dodge 518 Transmission Swap from a 727 Transmission

Pushbutton Shifter Conversion

Imperial Services

http://www.hotrod.com/techarticles/113_0705_engine_swap/a518_transmission.html

http://www.keislerauto.com/mopar/index.html

http://www.autohobbydigest.com/a-3spd.html

http://www.autohobbydigest.com/a-4spd.html

http://www.autohobbydigest.com/a-5spd.html

http://www.autohobbydigest.com/a-auto.html

http://www.slantsix.org/articles/4-speeds/ODA833fourspeed1.htm

http://www.slantsix.org/articles/4-speeds/3speed-info-swaps/3-speed-swaps.htm

A-390 Transmission Movie

http://drivetrain.com/vartransp28.html

http://parts.mackstrans.com/bkits.php

http://www.classicmopar5speed.com/

http://www.wilcap.com/ (Slant 6 to GM transmission adapters)

AR Engineering (Slant 6 to A500/A518 Adapter)

Nice adapter but ARE isn't offering it at this time because the last batch took too long to sell.  If you want one, you'll need to put down a deposit.

(see http://www.slantsix.org/forum/viewtopic.php?t=13144 and

http://www.slantsix.org/forum/viewtopic.php?t=16651)