Me and a friend of mine are trying to do some of the classic instances with our 60's alts. The thing is: while we can do Upper Blackrock Spire (10 man) with random 60's players, we are not going to get 40 guys for the large raids.
So, I'd like to know the opinion of people who already did:
Ahn'Qiraj Temple and Ruins
How many 80's are necessary to do these raids, while keeping them challenging?