my highest i will let my cpu go is around 45 idle..but thats just me
if u test ur cpu torture test in Prime 95 and its totally stable for at least 12 hours, then id say its safe, it doesnt matter how high it is, as long as its not past 50c on idle, then u know ur heatsink fan is just not cutting it
just test prime 95 for at least 12 hours at that speed and if it crashes, get a thermalright slk-900, 947 or sp-97, they are far superior to the wimpy aero-7+, sorry to say but ur hsf isnt that great
just try to stay below 50 idle and if ur oc isnt stable, then u can try burning in, what it basically does is it lets u hit higher oc'd settings at lower vcore (cpu volts), resulting in less heat
go here to find out how to set priority of prime 95
to burn in, all u do is lower the cpu speed as LOW as possible, like lowest fsb and lowest multiplier and have the highest voltage, then u leave prime 95 running for a day or two on the torture test that produces maximum heat, at max priority