The max temps are NOT the max safe temps that you can run your processor everyday use. At those temps, your cpu wont last very long.
Most recommended keeping your temps under 50*C, 55*C at the most. Yes dual cores give off more heat, but that doesn't mean they can take more heat than normal single core processors, after all, they are just two single core processors on one die (FX60 = 2 FX55s, X2's = 2 sandiego or venice cores). The extra heat is just one of the tradeoffs you get when running and overclocking a dual core processor.