From what I have seen most 5.3 vortec motors make their peak power at 5500 rpm. However on JBA website after installing their headers they made their peak power at around 4700 rpm. Does installing headers, make your motor make its peak power faster

 

It depends on what rev range the headers are tuned to be the most effecient.I would imagine that JBA's dyno is showing where their headers work best.Generally short tubes only boost topend performance,tri-wyes boost in the midrange and longtubes boost throughout the rev range.That being said it's the combination of parts that determine where horsepower peaks,not just the headers.Longtube equal length headers would at least in theory provide the greatest horsepower increase,but the longtubes that fit our trucks are a compromise in length,tube size and collector size.

 

I could feel my peak power change after my JBA install. At the time it was my only mod.