If you look at the right most gauge. It is near the heater motor switch, but not too close.
The openings for the heater seem to be in stock 67 to 70? Dash location.
The 67 thru 69 bezels and gauge clusters are mostly identical and can swap around (exceptions.... The 67 speedo has screw on cable, and the glove box door has side hinges and radio is post type vs later press on cable and bottom hinge and thumb radio)
So I think it could fit into the 67 thru 70 something dash frame.