The heater intake (box) on my mid 80`s +8 has no foam sealing, and also has a small hole drilled through its base, that may or may not be original.... (-: Pretty sure Kevin who restored it told me that the foam could hold dampness and in time cause corrosion of the box it`s self. Rarely running with the hood up a little heat or the whiff of underbonnet aromas was never thought to be a real problem in my local climate...
Each to their own... (-:
