You can try Updating the BIOS but I doubt it will make any differences in your CPU Temp's, it never made any in any of the Quads I run anyway. The main problem I see is that when running the PrimeGrid Project WU's is that your CPU can run 5c to 10c higher than when running some of the other Projects.
Also 1.55 Volts is a lot of Voltage to be running to get to 3.6Ghz, I have several CPU's running @ 3.6Ghz but their only using 1.40 to 1.45 Volts to get there. I assume your running some sort of aftermarket cooler on the CPU to run @ 3.6Ghz, if not then thats an option too, get a better Cooler.
I don't think 70c will ruin the CPU as Quads are noted to run fairly hot but I wouldn't want to go any higher, I had 1 running about 75c for several months until I put a better cooler on it and it never has had any problems yet ...
