Wes This is a close as I can get to answering your question about converting your 69 to a tilt column using other GM cars as donors. All this info was gathered for doing a column conversion in my 75. You will have to measure and check a few things. There are only 4 places differences in the columns can occur in 69 - 79 GM cars. The length from the mount under the front of the dash to the firewall, the length from the mount under the front of the dash to the steering wheel, the splined end that sticks into the engine compartment and the plate that bolts to the firewall inside the car. Many columns will fit, but remember that some of the parts used in each one may vary slightly and replacement parts would need to be purchased for the car the column came from.
This photo shows the 3 columns I have to compare. The black one on the left is tilt from a 77 Nova. It measures 13" from the housing just under the steering wheel to the center of the under dash mount, and 15" from the center of the mount to the floor plate and over all is 32 1/2" from the housing to the end of the splined shaft . The blue one is a non tilt from a 70 Chevelle and measures the same and the brown one came out of an 82 Eldorado and it also measures close enough to fit. The Eldorado is a tilt/telescopic so the distance from the mount to the wheel can be varied about 2".