Subaru Legacy 2003 Service Manual page 263

CYLINDER HEAD ASSEMBLY
MECHANICAL
2) Put a small amount of grinding compound on the
seat surface and lap the valve and seat surface.
<Ref. to ME(H4SO)-63, VALVE SEAT, ADJUST-
MENT, Cylinder Head Assembly.> Install a new in-
take valve oil seal after lapping.
ME(H4SO)-66