Edelbrock/cast head flow numbers?

I'm looking at the Edelbrock PN 60767 heads for my 360. I have a set of 596 heads that my machinist says are junk (bumps in the exhaust port...low flow). I was wondering if anyone has bought these Edelbrock heads and flowed them. Also, I have been told that the 308 head is much better than the 596. Can anyone back that claim up? My head options are 596, 051, 308, 576, 302, or the Edelbrock heads. Any help would be much obliged!
Wayne