Those CPU core temperatures look high to me. 56-57 seems high for an idle temperature, while 64-67 is high for the modest peak loads shown. My guess is load it up to 100% using a stress testing program will see the temperatures spike up towards the danger zone.
For comparison I have a Lynnfield i5 (same era as i7-920) and was getting idle core temps in the mid-upper 20's, with an AC Freezer 7 Pro CPU cooler. At 100% load (@ 3.6 Ghz) I was getting mid 70's. It depends on ambient temperature of course, but unless you're in the Sahara, they seem high. I would suggest checking the cooler is fitted properly. Clean it and the CPU with alcohol and refit with a small amount of thermal compound, making sure you follow the fitting instructions for your CPU socket type.