I'm the same size as you and skied a pair of 187 MSPs for a few days last season. Personally, I'd agree with the first dude that posted, saying 1 - 1.5 cm back from the freeride mount line is the way to go. You'll still be fine in the park, but they'll also perform waaay better outside the park.
The pair I rode were mounted 1 cm forward of the freeride mark and they sucked in pow and on anything remotely steep...too much tail.
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