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Cylinder Head Overhaul

  1. Replace cylinder head if surface warpage exceeds .006" (.15 mm) across its length or .003" (.08 mm) across its width. DO NOT machine cylinder head surface.
  2. Inspect prechamber for facial cracks. Replace prechamber if facial crack length exceeds 3/16" or if crack reaches head gasket sealing mark. To remove prechamber from cylinder head, insert small nylon punch through injector hole. Drive prechamber from cylinder head.
  3. To install prechamber, align prechamber with alignment notch in cylinder head. Using 1 1/4" (32 mm) socket and hammer, tap prechamber into bore.
  4. Measure prechamber installed height in 2 or more locations where prechamber seats against head gasket shield and sealing ring. Ensure prechamber is even with cylinder head or does not protrude from cylinder head more than .002" (.05 mm). Prechamber must not be recessed in cylinder head.
  5. Measure cylinder head thickness between valve cover gasket surface and cylinder head gasket surface. Replace cylinder head if thickness is less than 3.853" (97.87 mm).
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