Gentlemen First I agree with 64fleetside on this and have to Dis Agree on most of the rest simply because there Is No Shiftbox on 1960 and newer trucks,
Its Built INTO the column as a quadrant and 1st/rev selector and 2nd/3rd selector.
These parts used to be available from GM, but can be fixed as Brian has stated by welding up the tab that fits in the slot on the quadrant.
regards Steve Sr.