If you check with intel's webpage you can check the warranty limit for your specifig cpu.
Mine when I checked was 70C thermal limit and 1.5v voltage limit
Assuming that yours is produced after mine, it should be G0 stepping?
check with the intel webpage for your CPU and your MOBO webpage how it handles Vdroop.
Important thing is that what you set in your BIOS is NOT your idle Vcore temp.
CPU's highest core voltage is right after it comes off load, that voltage spike you do not want to surpass the Voltage limit of the CPU to be safe.
This is a good graph of how processor voltage change regards to load.
link
All the information above is what I gathered from hardforum.com, anandtech forums, overclocker.net, and various other overclocking discussion sites.
FYI, I've run my E6750 at 3.6ghz 450x8 1.4875v.
34c idle 65c load w/ CM hyper212 in a well ventilated p180 case