of all the threads and posts i have read in the SC forums, not once have I seen anybody even mention that they're pistons were bad. I have a spare motor with 200K (KM's) with good pistons, and the motor in my car now has maybe 140 K KM's (Bill help me out here), and it runs like a dream come true....
I'm sure your old pistons will be fine, but have them checked out, or impregnated.