Thanks for all the input. Hopefully I'm on my way to solving or at least lessening the problem. After a through going over, I found a rock puncture in the AC/heater box located on the outside firewall. I probably should have found it earlier, but it wasn't as obvious as you might think. I also found an area on the same box where some of the seal had fallen off, allowing additional air flow. I still get quite a bit of flow, but I think I may have a vacume leak in the system allowing a door to remain open or closed.

Darrell, did your various fixes solve the excess heat problem? I am having a similar problem with my '75 convertible. After an hour or so, even the shifter knob and the seat adjustment knob are too hot to touch. The driver's side is much hotter than the passenger side.

Kenn Garrison

I had the same problem in my 79 until I installed Koolmat..no more hot feet.. Here is their website for info.. www.koolmat.com

My wife's 78 was doing the same heat problem when she first got it. It was the heater not being hooked up properly. Are you sure you have all from the heater not coming into the cab? plus all the sealer and insulating tips sound good .

These cars are old and the original heater box seals have disintegrated. www.docrebuild.com sells all the seals necessary to rebuild the heater box. Most likely heat is coming through the heater box even though the door is closed. The disintegrated rubber seal is not preventing the dood to seal out the hot air. The easiest check for this is to disconnect the heater hoses going into the heater box/core and put in a connection available at an auto parts store, the hoses are different sizes and this union is cheap. If you heating problem goes away like mine did you need new heater seals in the heater box.