Thanks for the information.
I got an e-mail from Anthony Powell in Sherman, TX and he advised that no matter how similar these things look on the outside, they may be very different on the inside. The extra terminal on the outside of the case is not the only difference between the 67 and 68 controls. Although a different replacement may seem to work, the difference in the control may result in incorrect settings within the AC/Heater box.
He sent this prior thread that shows both controls dissected and the differences inside.
http://www.forbbodiesonly.com/mopar...ers-Disected-w-Pics&highlight=heater+controls
Thanks to Vfilms for going to the trouble of getting two separate controls from the 67 and 68 and documenting the insides. They are very different even when just one model year apart. This part supercedes that part may mean it is the new and improved version, but it does not necessarily mean it is a suitable replacement.
Allen Powell rebuilds these for $75 and replaces broken push button receptacles and vacuum nipples, as well as cleaning and lubricating the internals. His current email is a
[email protected]. His recommendation is to use the correct part number for the car. If you can get a NOS one, it will probably be okay even if almost 50 years old. A used one will most likely need to be rebuilt after all this time if the buttons do not work freely. Your old one can be rebuilt for $75, even if all the push button receptacles and vacuum nipples are missing.
A NOS one for my car is $300+ and hard to come by. I am going for the rebuild and using the correct part. After all the money I have spent on getting the factory AC back in working order, I am not going to cheap out now and screw up my new wiring harness trying to wire up the wrong control, or end up with the AC not working correctly and having to pull the dash apart again.
Thanks to everyone who responded to me on this.
Don
