We get this question quite a bit. Make sure to reference this article after you’re done reading this one. The important thing to keep in mind is that we don’t want any flex in the pushrods. You probably remember from this May article that flex in the valvetrain results in loss of horsepower. Flex in the pushrods reduces the effective length of the pushrod, resulting in less lift.
One way to reduce flex is by using quality pushrods with a wall thickness of .120″. For all of our Race Series and Endurance Series Roller Rocker Arms, we recommend a 5/16″ .120″ wall thickness like these from Custom Built Motors or these available from Summit Racing.