You drain the coolant first, then change the intake manifold gasket, then refill coolant. This is a good time to change thermostat.
If coolant gets into oil pan, you can wash the main bearings causing a lot of damage.
If the head gasket is blown, you will have to remove heads, check for warpage and install new head gaskets and headbolts (along with intake manifold set).
If the head is cracked, it must be replaced. You may want to research a used low mile engine, it may be cheaper in the long run.
You always drain coolant first when changing intake/head gaskets.
Thursday, October 16th, 2008 AT 8:59 AM