[Alfisto Steve]

I THINK item 63 ceramic heat sink IS PART OF CAT CONVERTOR TEMP LIGHT SYSTEM. Have a set of item 62 relays, too but not sure what they are for either.

 

[Alfisto Steve]

Yep only the round waffle pan shaped cat with perforated heat shield had that system. However comma now that I think of it the early 81-83 GTV6 had something similiar and did not have round cat.