is a 750 cfm Demon double pumper to much carb for a mildly modified 351 Cleveland (Mild grind cam, roller rockers, MSD, headers? I am currently using a Holley 650 CFM. I have also found a NIB Demon "Speed Demon" 650 CFM, mechanical secondaries for $300. Does anyone have an opinion they would care to share about Demon carbs Vs Holley's? Boyd