I use the repo 64-67 Chevelle boot. It's the same as the 65-66 GS (with console) LOWER Boot..... However the console has a second boot (upper boot) that fits in the console.
The upper boot is repo'd for the later GS's that have the rectangular shifter handle. No repo avail for our round-stick GS's tho.
The Hurst shifter is in a slightly different location. Might not fit the console real well unless you move the console or get an offset shifter handle.