The heads are the 58cc versions. No idea what before and after HP ratings are, but believe me, you'll know it when you punch the gas. If you're worried about that, you surely shouldn't be.
As for the roller rockers... All the Keith Craft AFR heads are stud mount, so you'll need the stud mount roller rockers. I chose the Scorpion from Keith and am very happy with them. In my opinion, you should opt for the Magnum pushrods instead of the cheaper hardened for reasons mentioned above in a previous post.
Let me know if you have any more questions. I just did this upgrade a couple months ago, so it's still all fresh in my mind.
