Here are just a couple of things to think about.
The heads are nice, but i think a solid 650 may be a little hard to reach with them. I think you will be in the ball park, but based on the article below, it may be a little difficult to actually reach that goal. Below is an article about a motor vey similar to yours. The cam has a little less duration but quite a bit more lift. This motor made 625 hp.
http://www.compcams.com/Community/Ar...ID=-2023343081
In order to safely meet that goal, I would recommend getting a little clean up port work done on the edelbrock heads or considering the AFR 305 or 325cc heads with the CNC combustion chambers. You can get a set of those from AFR assembeled for $2500. From what I could find, The edelbrocks are ~$2000 for a set.
At any rate, based on what I have been told by many people with similar engines, the edelbrock heads should be able to get you your mid 11 second goal pretty easily even if they dont quite reach 650 hp.
Adam