a kid in high school did that on a chevy. [i can't recall the year or model]
just left off the reverse rod.
a blocker would be good to have, but i would have to study the mechanism to see if it could be feasible.
i can't say how a pistol grip 4spd shifter would bolt up, or work on, a 230 transmission.
there would more than likely need to be some trinkity work needed to make it mount and operate. i wouldn't think it wouldn't be anything major.
however, it might be a ton easier to just wack off a chunk of the pistol grip handle, then weld on a triangle shape with the appropriate sizes holes for the 3spd inland shifter, then just bolt it on and go.