Leaking exhaust manifolds can be annoying and if left alone can lead to burst exhaust valves. Here's how to stop a leak:

A.) Check the manifold flanges with a straight-edge and a feeler gauge.

You shouldn't be able to slide a .010 inch feeler gauge under the straight edge. Clean and resurface as necessary (a belt surfacer does a good job).

B.) Soak the manifold gasket in water and using a blow drier, heat-shrink into place.

C.) Use high temp copper silicon around each of the port openings. (Note: the above works only on traditional asbestos-style gaskets.)

D.) Because access to the studs or bolts will be limited, use a Snap-on brand high performance 12 point socket with it's thinner walls. The lower priced imported sockets have very thick walls.

E.) To prevent the bolts from loosening use a high temp silicone sealant like Lock-Tite.

F.) Tighten in a circular, hop-scotch pattern as you would a cylinder head. Re-tighten after 10 hours.