does anybody know how to figure out what type of tranny it is, i have been asked if it is a fmx, c4, or c6. i know it is a 3 speed manual and i see some writing on it but i don't know how to figure out what it means. help!

i have a transmission out of a 1973 mustang for sale. it came with a 351 cleveland engine back in 1980 and has not been used since. i am located in long island, new york and am looking to get $200 obo for it. pics available upon request

 

if its a 3speed it is not a c4, c6, or an fmx tranny

 

lol than what kind could it be, i knew the c6 was an atuo i wasnt sure of the other 2