Spamfreedom wrote:

BTW, it seems to happen after the engine has sat for awhile
(months) and during cold weather starts....

It sounds like you run the engine infrequently, at low loads and it
never really gets hot ... is this close?

If that is the case, you probably have carbon deposits on the valve
stems and lack of lubrication, particularly when starting cold, can
cause the valve stems to stick and bend the pushrods.

You can avoid a lot of this by making sure the engine gets up to
operating temperatures when loaded and then idles for a few moments
before switching off so that oil cannot carbonize on the hot valve stems.

Rick