Tech...I did that mod lots for guys back when. Start with a shifter that has a solid lever, and weld a stick from an old floor shift trans to it, looks better than those wimpy '50's column sticks poking through the floor. You end up with a wide neutral gate, but they do work.
Sickiee...no better engine in the world for a Deuce than Henry's finest! The '49 and 3 speed is a sweet combo for everyday use, probably the smoothest of all the flatties.