Where is the heater blower motor located on a '67? I guess it just has one speed as there is no speed control, right?

 

The heater blower motor mounts to the left hand side of the firewall in the engine compartment. You will find it tucked under the front left fender.
Speed control is located on the heater control assembly on the dash.

 

OOPS!
Right side - Right fender - Passenger side!