Photo request. 1966 dart manual transmission stuff

Yeah, no factory 3 speed floor shifters in '66.
That said, waaay back in the day I converted a '65 to a floor shift using a Hurst "Indy" 3spd conversion kit. Made my own small hump out of sheetmetal, didn't take much.
HATED it. Non-synchro first gear in those trannies takes a lot of the fun out of "rowing it yourself" in traffic.
Your decision, but I'd give serious consideration to hunting down a 4 gear, or at least a later model 3 spd ('70 & up?) made for a floor shift.