I already received a new intake valve rocker arm in the mail today.
Recall that I had previously set the valve lash to spec with the old rocker arm, which I thought had been bent.
So I took the old one off, replaced it with the new one. And it became immediately obvious that the old rocker arm was not bent.
So I don't know why I have developed a mysterious 0.040" valve lash. I am going to make up a temporary paper cover gasket, put the machine back together, fill it with oil and see what happens.
It the engine starts, I imagine it will kill itself in short order. I'll be back in there either replacing a broken rocker arm, resetting the valve lash, or who knows what else.
I'll report back tomorrow.
