You can buy add-on 4 way hazard flasher kits if you want to add one. From 67-69, the hazard switch was on the dash. You could build that yourself if you can find one of those switches. "Good luck." The way it works is this:
With the column TS switch centered, the two rear turn/ stop lamps are connected, and are connected to the switched brake line coming from the brake switch. You also have the two front turn wires
The 67-69 switch has 4 terminals. None are interconnected when off, and all 4 are interconnected when on. You wire any terminal to the brake switch line going to the TS column switch, and wire any other two to the left and right front wires. Then you wire an "always hot" flasher to the 4th terminal. So when on the hazard flasher feeds "flash" power to the brake switch line, and to each front lamp