3 speed floor shift conversion

I'm looking to swap my car to a 3sp floor shift from factory column shift. It's a 1971 Demon Dart. (I know Noone offers these but I am a metal fabricator and feel it's worth my chances w/ a Mr. Gasket model #7667a)

If anyone can give more insight on compatibility and fitment that'd be great. But I am looking to buy one for a reasonable price. (Mr. Gasket discontinued this item and I'd hate to buy the Hurst equivalent beings I just need it till I do the 340/4spd swap.)

I'm located in Kansas City MO and am willing to pay shipping. Lmk what you got.

Thanks,
71_Scatpack