... I'd say we can't tell you anything without knowing about your ride. It may well be the same considering other limiting factors. horsepower is made as a system, not as piecemail, although you'll certainly see a bit more low end. Considering a low lift cam, a poor ignition system or springs that are weak and old may be your limiting factors, your new set of headers may well do nothing for upper end efficiency; i.e. horsepower.