Jerry- the tube's main function is to supply oil to the top of the head to allow it to flow outward to the rocker arms- here's another diagram from Tim's website. It's from the bottom of the page he linked for you.

A lot of the tubes were crimped exactly where you say your oil line is broken; look at Tim's website link of the rocker arms and see if this is what you are describing.


Brad


Wrench Fetcher, PhD