That is a good point, and something I hadn't considered. General consensus I get is headers don't do anything for an engine that wasn't designed with performance in mind, except change the exhaust note. (With obvious exceptions being manifolds that were a bottleneck in the first place.)
I would have to disagree with headers doing nothing for a stock engine. Getting burnt fuel out allows unburnt fuel in. Take the stock logs on an early A and replace with a header and you will feel it even with a 2 barrel.
