You mean chain guide cover bolt not head bolt.

10 N·m normal for m6 into aluminum. I'm sure that was close to what I've used for all the bolts holding the chain covers on the m62tu. I would maybe err on the side of caution and use 9.

Also did you use permatex in any corner and the gap under the valve cover? (If like the m62 the VC bridges over the head into the guide covers. Prob any ohv engine does this)

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)