The only difference I know of between the 70 & 72 A-Body tracks is the 70 tracks have a wire from the driver side to the passenger side to allow for adjustment. The 72 tracks look almost identical except the passenger track just slides/follows along & doesn't need the wire to activate the lever....
are these 72 tracks for a A body,the one track don't have any lever and just slides along ,they look just like my 70 set but no lever and wire attaches to the other track.thanks