Is there an easy way to determine where a part goes on an airplane? In order to classify parts for export I need to determine where our parts go on the plane.  (Engine or structural/body)  Specifically looking at the canister, heat shield assy and lock support for the Boeing 767/777.
What you need is a parts catalog/diagram. 

Here is one for the 767 that shows parts and where they go. Interestingly all the pictures seem to be of the BBJ (business jet) version of the 767, the other parts should remain the same.