Yes it should be used cause it has a switch pitch converter. Which are nice to have since it acts sort of like a kick down. Nice to use while passing or on inclines.
Ok. First off all dynaflows bellhousing unbolt. The Dual path which looks like a dynaflow but smaller dnt. 57-63 bellhousing use the same part number. (1171803). They'res different lengths dynaflows thou. It's the tail housing and output shaft that varies. In 1955 40-60 series used a 9 3/4 tail...