I just wanted to ask opinions on correct carb sizes out there. I have seen the calculators and read the materials and they seem to contradict. The only thing that does not is that most people put on too large of a carb in regards to CFM. I had a 289 punched out to 292, large cam, heavily ported, balanced and able to spin to 7500 rpm max. I used a 650CFM mech secondaries Mighty Demon (4 speed car) and it was way too rich unless I ;leaned it way out, then it hurt performance. Books say 525~600 cfm for this engine assuming the VE is 80% minimum. I am building an Edelbrock packaged engine (#2091 top end kit with 9.5~1 CR) and spoke to their tech people who said they made 350hp numbers using a 750 cfm carb. This is not a streetable setup using this, just a method to get good HP numbers My question is I was going to use a 575cfm carb for this same package and was wondering how much this would hurt HP. It will definetly help driveability so that is the pro.I am not a fan of vacuum secondaries as I like larger cams so I will be putting a mechanical secondary carb on. Any feedback on what you guys are running and pros/cons of each? Brian