Difference between pre-1966 and post 1970 steering columns

Totally different.....as in no dimension is the same.....length, diameter, dash bracket, floor bracket, turn signal switch wiring, steering wheel, etc...... By manual column, I'm assuming this to mean manual steering? Not manual transmission? If you just need to swap the center shaft on your column from P/S to manual, That shaft and coupler will swap from '63-6. The couplers have a few versions that look different, but all the manual couplers those years will work on the stock manual steering gear.