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.
What if you cant get a .120″ wall thickness pushrod in the length you need?
I would like to run a .120″ wall thickness as AFR recommends it as well, but half lift method tells me I should run a 6.50″ length pushrod. AFR states stock length or stock length + 0.100″ which would be 6.25″ or 6.35″ which I could get .120″ in 6.35″ length but not sure what kind of contact pattern it would give me considering how its 0.15″ shorter than what half lift method says I need.
Good Morning Matthew,
Please give Norm a call to go over your pushrods. (352) 512-0800