We all need to start somewhere and looking inside your engine is definitely the best and most reliable place to start.

Take a good look inside even if only through the oil filler hole.
Oh, and you will need a torch, a Penlight is best.
A good look inside the rocker covers through the oil hole will help you to determine the internal condition (and the minimum parts you will need for a successful job).

If your are unsure, it will fall into one of the following categories.

• Silver Alloy surfaces? In this condition it should be like a new engine.
• Light brown tarnished? Probably very low mileage and well cared for.
• Darker brown tarnish? Perhaps high mileage but still well cared for.
• Black? Getting poor, a full rebuild/replacement should be considered.
• Black Coated & becoming dense? Very poor condition, A rebuild is normally required
• Black and very sludgy? Dead on its feet.
   
  You can be sure this method is a reliable way to determine what you have, and to help you decide what you should do.
  
  NOTE: Please be wary of engines that have been partly rebuilt where the above information may be confused.