All Small Six Curious Why Pushrods Are Made In 2 Different Diameters

[TrickSix]

I picked up a bunch of the adjustable rocker ball and cup pushrods recently. As I cleaned and checked them for straightness, I noticed that they had two different shaft diameters. Some are about .270", and others are .314" or so, including a couple of the new aftermarket ones I already had. When I checked some spare non-adjustable ball and ball pushrods I saw the same variation. I'm curious about whether the thinner ones were prone to bending and so Ford beefed them up at some point, or if it is just from random supplier variations.

 

[DON]

I am not sure what came from ford, but aftermarket ones that I have dealt with you have a choice if diameter and wall thickness as well as oil restriction if needed. Stock cams/springs require less of pushrods than aggressive cams/ springs do. There is probably not a definite line on when you need heavier PR, more of a range or gray area where you could go either way. Some on this site might be able to put numbers in. Stock/ slightly modified cams will be fine with stock