I will have agree with you. I had a 383 with Performer dual plain intake and switched it out to a Weind single plain thinking I would gain HP and TQ. I didn't change anything but the intake and the performance went down hill quick. It wasn't long I switched the Performer back on. The single plain looked good on the motor but man it robbed horses. I guess if I was leaving the line at or over 6000 RPM it have worked good. LOL!