Nopes, 8th was never legal with Ravnica, I believe. Ravnica was legal with 9th (release Jun 05 - before Rav), and I'm not sure if it was legal with 10th (I believe for a short period, at the end of Rav-TSP t2?)... Alara was the block after Lorwyn, so that would be 10th, M10, and M11, I believe...