Charlie,
Sounds like you have a nice truck with a good history. You might wants some shop manuals for both the truck and the engine, if it is not the original. Here is a link to
the manuals on the Old Online Chevy site, and here is a link to a source for
later (post 1955) manuals, some on CDs. You need to find out which 235 you have, as there are different methods for getting oil to the rocker arms.
Are you getting good lubrication to the rocker arms. That can also be a cause for broken rocker ars and bent push rods.
Hoyt
