No sealers are needed for the head gasket, but this job involves removing the upper timing cover. This timing cover requires sealer. Check the link Arthur Dalton provided, it names the specified sealer.

The head bolts may be reused, depending on how much they've stretched; there's a specification for this. Torque is 55 Nm + 1/4 turn + 1/4 turn.

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95 E320 Cabriolet, 169K