Yes and No,
The best blue cores are the 750's week 24. The 800 could probably only overclock to 900, maybe 1gig but that's rare for a blue 800. I have a week 23 blue 700 and it runs at 850 default voltage, 900 @1.85V. My 750 Week 24 blue runs at 1.1gig@1.85.
Alex