Hello
Do you still need help with the firing order?
The 351 firing order is:13726548. It is the same as 302Ho
The 302 firing order is:15426378.
The biggest question is, Is it A solid or Roller cam? This will determine what valve lash you will use.
Remember the more you rotate the engine the more you ware the parts. So try to turn it as little as possible, Or get a good drill to pump the
oil pump as you work.
Paul