As Leo mentioned, the actual ign switch (on TOP of column, under the dash) can be used from your existing column. It has to be flipped over because the actuating rod (that comes down from the lock cylinder) moves in opposite directions for tilt and non-tilt columns.
Columns UP TO 1978 will interchange (A-bodies, Camaros, etc). The 78-earlier steering column shaft/coupler had splines. In 1979, the shaft/coupler changed to 2 flats for the shaft/coupler. Several years ago, we installed a tilt column from a 1978 Z28 into my son's 71 Chevelle. Perfect fit, zero modifications! BUT, about 1976, some bolts/nuts were metric, so if you use a later column with metric fasteners, save and use them (the ones I'm referring to are the 2 which attached the column to the underside of the dash).
Columns UP TO 1978 will interchange (A-bodies, Camaros, etc). The 78-earlier steering column shaft/coupler had splines. In 1979, the shaft/coupler changed to 2 flats for the shaft/coupler. Several years ago, we installed a tilt column from a 1978 Z28 into my son's 71 Chevelle. Perfect fit, zero modifications! BUT, about 1976, some bolts/nuts were metric, so if you use a later column with metric fasteners, save and use them (the ones I'm referring to are the 2 which attached the column to the underside of the dash).