[b-man]

I went with the thicker .118”” wall 5/16” Manton pushrod on my relatively mild 421 HO build, 068 cam with 1.5:1 Crower stainless roller rockers and spring pressure around 250# over the nose.

Pushrod stiffness is most enhanced by using a larger diameter pushrod. However when you’re stuck with a 5/16” pushrod it can’t hurt to go for the thickest wall available.

Less pushrod flex is always a good thing.

A stable valve train ensures reliable performance.