If your motor mounts are known to be good and the shocks to be bad, replace the shocks. Raising the idle is just hiding the problem. For your gasket, just replace it. I am assuming you're talking about the lower oil pan gasket.

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member