thanks guys. I talked to TireRack and Koni today...both have great customer service.
Koni said that does happen on occasion but those nuts should still work, just torque them down. I'm going to double check the threads on the one that wasn't going on and try a little harder (without stripping anything) They're also sending me some nylon insert nuts that will replace the square nuts, so that's cool.
I also was missing a M12 nut for the strut shaft and they're sending me that too.
So now I'm in my garage...take 2...
[edit 5 minutes later...] yeah both square nuts fit fine with only hand-applied force. Must have been all that yellow paint
