While I certainly agree with the ignition comments, an engine is composed of many parts, and the performance of the engine is a result of how well each of the parts like its neighbor!
Consider this FACT:
When Mr. Duntov built a race only 283 CID engine for the 1957 Corvette, he chose a single Carter type WCFB, number 2493s.
The Carter 2493s was rated at 380 CFM !!! And you have 600 ?????
Even the 2493s would probably require some modification to work well with your specific engine.
Jon
