Originally Posted by Big Tee
. . . Also, not to be nitpicky but I am not sure a factory 4 speed on the floor came in a 1951 3100 but I could be wrong.
A regular production option for 3100s in 1953 was the SM420 4-speed (shifter through the floor).

http://chevy.oldcarmanualproject.com/chevyresto/53153.htm