QUOTE(r_towle @ Jul 18 2018, 07:27 AM)
Until you really want to fix it, which may take a while...
Remove the two rubber hoses that connect the flappers to the chassis tubes.
Grab two standard spray paint (rattle can) covers and put them over the tubes that lead into the chassis. The right ones fit like a glove.
Use a couple of large screw clamps that held the rubber tubes in place.
Now you will have time to remove the flappers and see what is going on while you can safely drive the car.
I discovered yesterday that there was sufficient tension on the heater box cables to allow heat to get into the cabin. I put slack in the cables so the flaps could close. As an extra measure, I removed the hoses. I'm going to be using the car for some events and it's certainly hot enough outside where I will not need a heater.
Your suggestion to cap the firewall tubes is a great one. Thank You!
Over the winter I'll pull the heat exchangers and do another pressure check.
Thanks everybody for all the help.
Jack