The good news is that not much changed in the columns that you are interested in.
69 and older have the key in the column and these are no help for you.
In 70 they went to the Key in column but the 1970 year also several unique features. A bolt held the lock cylinder in the column and there was an interlock system that required you to be in park or Reverse to remove the key. These are not worth your time, leave them for the 70 specific restorations.
In 71 and later they had 4 column types. Auto(Column shift), Auto/Manual (Floor shift), 3 on the tree, and tilt/telescoping. The Tilt/Telescope were actually GM columns.
They continued with these until late 80's early 90's on vans and trucks. I have used late 70's / 80's truck columns to convert Column shift auto columns to manual columns. Parts are easy to get from trucks/vans.
After that it is really just the shaft and extension tube that is the difference. That is why you probably won't see a whole lot of diagrams from later than 71. They really just didn't change. They did add a flex coupling in 73 and later B bodies because of the rubber isolated front K frames added another level of flex.
If you are getting a column check the length of the extension tube, and since you have a 74 you will have a flex coupling just past the base of the column. These were a metal & rubber biscuit that usually falls apart. The early ones were about 5/8" to 3/4" thick and are hard/expensive to find. You can stack a couple of the easily found later flex couplings which are about half as thick and made from nylon reinforced rubber (think tire tread with out the actual tread). These are available at Autozone.
Hopefully that is some help.
