I am usually in agreement, but not on this one..
The Lower gaskets are made of Nylon 66... But over time will degrade, with the car being as old as it is, do not use the stop leak or silver to seal this... The gasket replacement is a must... I have seen these in cases look like complete garbage, and some were leaking coolant internally for a long period of time unknown by the owner... These nylon gaskets are not a life long gasket.. Replace the gaskets and let the car live on for a very long time to come..
In some more extreme cases the lower intake may be pitted around the coolant ports...