What's a good voltage for a Duron overclocked to 1GHz?

[PlunX]

Somehow, my old Duron 600MHz got messed up when I was trying to overclock it to around 1GHz.. Tried 1.8v in the BIOS (seems as though programs show that my actual vcore is .5v more than what the BIOS says) and the motherboard beeped.. Reset the CMOS, same thing. I was running it stable in windows at 950MHz just before then with temps at 35 C. - 39 C., so.. I doubt it got burned up.. But, something happened to it and it died. Anyway, I got a Duron 800MHz even though I heard that they don't overclock well.. I'm running it at 900MHz right now with 1.77v (set 1.7v in the BIOS but MSI's motherboard monitor shows 1.77v) without any problems at all.. 4500 RPM fan blowing directly at the 6800 RPM FOP38 fan, 28 C. CPU idle temp and 26 C. idle chassis temp. I know that these temperatures are right since I can put my finger at the base of the heatsink where it touches the CPU and it doesn't even feel warm. I -really- want to try 1GHz, but I don't want to rush into things.. Should I do it right now or should I let the processor burn itself in for a few days? Whenever I decide to do it, what voltage should I use?