DO YOU REPLACE BOTH UPPER AND LOWER MANIFOLD GASKETS,I AM NOT CAR SAVVY
My car has 115658 miles.
My car has an automatic transmission.
It depends on what you are doing. If you only need to replace the upper then replace just the upper. If you need to do the lower then you will need to drain the coolant. On these engines, they leak coolant at the corner of the head gaskets and lower intake. The heads need to be removed to fix the problem, if this is what you are looking at.