Quote: B & E body use a "donut" type seal that sandwiches between the firewall and heater box. A-body boxes don't have a flat surface on the box for a donut seal to seal against.
Hi Rick. Hope you are doing well! The firewall is where the plate is making contact against the thin foam gasket. The plate is actually doing nothing to assist in the sealing capabilities of the hoses. The seal area is provided by the clamps forcing the hose against the flared area of the heater core (outlet) pipes. It appears that the firewall surface could have provided the same “backing surface” as the plate. I have not taken this area apart so maybe I am missing some hidden aspect.
