I have just gone to an Edelbrock intake and brand new Holley 1848, 465 CFM carb on my stock 260 motor. At about 2500 RPM, when the throttle is opened there is a pronounced flat spot until finally the rpm's climb. I believe it to be an accelerator pump that is not in proper adjustment. Anyone been through this and how did you adjust the sqirt to alleviate the flat spot ? Would the flat spot indicate momentary fuel starvation ? No backfiring. Thanks.