If there are no cracks.
I would suggest chasing all the threads on the cases and bolts. Clean all surfaces, new base gasket of the correct thickness (check squish first without a gasket to determine correct one per manual), apply a very thin coat of 1211 to the base gasket, grease and seal bolts and torque per manual with the exhaust manifold on.
If it still leaks there is a crack or something is warped.
I would suggest chasing all the threads on the cases and bolts. Clean all surfaces, new base gasket of the correct thickness (check squish first without a gasket to determine correct one per manual), apply a very thin coat of 1211 to the base gasket, grease and seal bolts and torque per manual with the exhaust manifold on.
If it still leaks there is a crack or something is warped.