Well, you'll want the key in the column so that limits you to '70+. '70 had that weird column interlock thing, so, you probably don't want to deal with that. '71+ should work, but keep in mind that the wiring harnesses changed some, so '73+ would probably be better.
But really you don't need the whole column, all you have to do is either swap out the top collars or convert them. You can remove the shift tube and linkage if you do that, and the rest of the stuff isn't different. There are a couple of "how-to's" depending on your skill level and available equipment for converting what you have
Automatic to Manual Steering Column Conversion "HOW TO"
Modifying Auto on the Column Steering Collars - NO Welding Required!!
Or you can just buy a used set of floor shift collars, they come up all the time. Here's a set on eBay now... (not mine!)
ORIG MOPAR FLOOR SHIFT STEERING COLUMN CONVERSION PARTS 1970 72 73 CUDA CHARGER | eBay
Or, they now reproduce the collars. Not cheap, but cheaper than buying a used floor shift column usually.
Mopar 71 72 73 74 Charger Roadrunner Dart Floor Shift Steering Column Collars | eBay