Did you read my guide? I stress it with 2 Orthos for 8 hours at LEAST.
What kind of cooler do/did you use? (And maybe reread the first 5 posts?).
I use the Zalman CNPS 9700LED. Very good cooler.
Oh and 3.0ghz in theory is always possible with any component. Even really bad 667 ram, with Q6600 and g0 stepping. If you hvae old B stepping you'll defintly need better ram. (Nearly even better cooling).
But i had 1GB generic 667 ram, Q6600(stock cooler), 7300GT, p35-DS3L Generic PSU(550w), not very well ventalated spot. For my comp for ages... had it 3.0ghz for ages. (The day i could get g0 Q6600 from supper billing... wouldive been a while ago).
So its very very possible to get 3.0 ghz
.