I owned both a 1967 and 68 and by brother had a 69 bird the rear heater hose goes from the heater core in the fire wall to the passenger rear cyclinder head just behind and a little below the rear intake runner there was a nipple on the head, the only coolent passage on the intake manifold was at the front for the upper rad hose, the other heater hose goes from the water pump to the firewall. I hope this helps.