Rebuilt a few VX 20XE engines. Still have one that one day will be put to use. A good way to learn is to take it apart and have a look and these days using your phone and taking pictures along the way will be helpful when you rebuild.
Built a few engines, only thing ive never done is removed/fitted valves and springs. Always sent the head away to get it checked and the valves springs and ports done at the same time.