I have the deluxe heater box with factory air in my '65 C30. It has the under hood heater box on the right in the picture below. I am trying to R and R the heater core but I cannot remove the top from the heater box. I have removed all the sheet metal screws and the five bolts holding the warm air manifold to the firewall. Do I need to remove the whole assembly and split it open on the workbench? The under-dash situation inside the truck is more complex and cluttered because of the factory air so it would be nice not to have to disassemble all that to get to the mounting studs behind the blower motor.
Advice? Thanks!...ned.