Yeah Cobalt, agree on the cfm upgrade. I was thinking of 750-800 range.
If you have a good speed shop around (and there still is a few) I would go in and order something up for a 454 or 502 and go from there and try for some feedback from the counter man with experience as ordering stuff like that sometimes get's confusing on the net.
I've always been a Holley man, just my preference, because I understand them more and Their easy for a simple guy like me to adj. It amazed me to also find that all the sprint cup cars use them exclusively. Hammer down!