Cool stuff but header making is a royal PITA. And then you read stuff that Calvin Elston writes and does and you realize that no matter what you do, you are probably leaving power on the table.
IMO, designing headers starts with the carb/induction and moves to the intake port and then to cam timing, then on to the exhaust port and cam lobe and THEN you can start thinking of header tubing sizes, steps if any, collector sizing and shape and design.
Calvin is as smart as they come. Reading his stuff makes you think about systems instead of parts.
