You just got to love those Big Block Chevy Heads. So, now that you have them you’re thinking is there anyway to improve them?
     Porters know what we all know, that is directing the air flow makes it better. The air wants to run down the top of the port and makes the bottom of the port just not that important.  Reducing the size of the intake runner increases the velocity and really seems to improve the performance at the track and on the street.
     Pictured below the inserts on the left are right side up and we have turned the ones on the right over so you can see how the casting follows the shape of the port.