The flapper valve for the heater needs a cable with about a 4 inch throw. The cable I got for this purpose only has a 3 inch throw. In addition, I wanted the heater "off" with the cable pushed in in the cockpit and "pull for on". A direct instalation of the cable to the flapper valve would result in the opposite.
To solve both problems, I decided to design and fabricate a bellcrank. I used the high tech items of tongue depressers, hot glue, aluminum, and a pop rivet to do so. See photos. Once I was satisfied with the design, I fabricated it out of various aluminum stock and hardware.