I looked at all the areas that should be sealed in the firewall. They were all sealed. I installed a hot water shutoff valve as part of the A/C system. The result was HOT Feet. Upon further investigation, I found the the plenum was not sealed to the fender. The top portion of the fender and the top portion of the firewall were not bonded together. This left a 8 inch by quarter inch gap to let all that 200 degree air in the plenum and to my feet. The faster I drove the hotter it got, no wonder. If you have tried everything else you might want to look in this area. I never would have guessed that this would be the cause.
Bill
Bill