I couldn't find the max temp for the newer i5-3570k, but yours seems high. Intel rates the tCase temp at 67.4C. But I don't know how that relates to T/J Max temp. Personally, I would not run Prime95 for an extended period with a stock cooler.
The temperatures are fine but you can bring them down a good bit with a good 3rd party HSF. Like InvalidError said you can add the Cooler Master hyper 212 +/Evo bring the temperature down a good bit. Heck adding another 120mm fan to it can bring them down even more.