The life of the engine unless the engine overheats.
Most head gaskets do in fact last the life of the car. The major cause of a head gasket failiure is lack of antifreeze in the system. antifreeze contains corrosion inhibitors which prevent the head gasket rotting and then blowing.
The Intake gasket is leaking, NOT THE HEAD GASKET. Replace the intake gasket
Normally it will last the life of the engine. However if the engine overheats the gasket can be ruined immediately.
You do not repair a head gasket you replace it with a new gasket which requires removing the head.
The head gasket seals between the head and block. The head gasket is inside the engine, up high.
The head gasket is sandwiched between the head and the engine block.
You can change the head gasket by removing the valve cover. Remove the gasket and clean the gasket surface. Put the new head gasket on the cleaned surface.
Remove the cylinder heads from your Chevy engine. Remove the head gasket and clean the head gasket surface. Put the new head gasket on and reverse the process.
Remove the cylinder head from your VW engine. Remove the head gasket and clean the head gasket surface. Put the new head gasket on and return the cylinder head to its original position.
A new head gasket.
The only repair for a blown head gasket is to replace the gasket.
You will need to remove the cylinder heads. Remove the old head gasket and clean the head gasket surface. Put the new head gasket on and reverse the process.