Great point/question.

If a/that valve stuck....., cam lobe still rotates, raises push rod (is it still straight?) and weak link expires.

Ugh. I don't like hearing that. Was that on your tiger with the big motors in it?

my thought was they are all on the edge and this spring is shimmed a little more or has a little shallower seat, causing this to fail first with more on the way. Engine guy building one after the next takes a shortcut and doesn’t check every single spring... Unlikely but an easy check

On another note, I am a steel rocker guy, aluminum is just not right for rockers IMO

it was a top gun. My buddy got a good deal on it because it had a broken rocker

LOL...broken rocker on a tired engine. I think both people involved in that transaction walked away happy. That's all that matters!

he did get the rest of the season out of that motor so he was thrilled! Lol hope your doing well in retirement land.

At least it was a clean break right on the end. When they break and send needle bearings into the motor that can cause damage quickly.

I would look at all the geometry and pushrods. Lots of natural deflection in a big block. A new rocker shouldn’t fail that fast. Likely an underlying issue in the valve train

I called Jesel about the known and common failures on these arms prior to using them.
the engineer told me that they break at the adjuster when guys over tighten the adjuster locknut.

i believe the spec is 22 ft.lbs.

he was adamant that this was really important to avoid cracking them at the adjuster.

What's your valve stem to guide clearance? Most heads come delivered set up for the street, you need a bit more for hard marine use.