Cylinder Head

CLEANING
Clean all surfaces of cylinder block and cylinder heads. Be sure material does not fall into the lifters and surrounding valley.
Clean cylinder block front and rear gasket surfaces using a suitable solvent.
Clean the exhaust manifold to cylinder head mating areas.

INSPECTION
Inspect all surfaces with a straightedge if there is any reason to suspect leakage. The out-of-flatness specifications are 0.0007 mm/mm (0.0004 inch/inch), 0.127 mm/152 mm (0.005 inch/6 inches) any direction or 0.254 mm (0.010 inch) overall across head. If exceeded, either replace head or lightly machine the head surface.
The cylinder head surface finish should be 1.78 - 4.57 microns (15 - 50 microinches).
Inspect push rods. Replace worn or bent rods.
Inspect rocker arms. Replace if worn or scored.