2wd vs 4wd columns are different in 79. On a 4wd the rag joint is close to the fire wall, basically under the master cylinder. On a 2wd it's closer to the steering gear and roughly next to the power steering pump. The inner shaft in the column is longer on a 2wd column.
I don't know exact years but not all years use the typical passenger car style rag joint. 79 and 80 do for sure, earlier uses a completely different coupler and I'd have to dig out the book to refresh myself on the detail. Another thing to watch out for when rounding up transplant parts is the bell crank for the shift linkage. 80 / down has a flat lever for both the trans side and the column side. 81 ish / up has an offset lever for one of them which results in a different throw length. Ya can use the later bell crank with the earlier column but ya gotta flatten out that lever and putz around with it to line up the shifter positions.
