Bolt (M10), Alternator @ top bracket, for 90~95 ZR-1 LT5. One (1) bolt is required per engine.  This is the top bolt for the upper alternator bracket (diagram #6) and also secures the alternator Fan Guard (diagram #2). 

See Part #4 on the diagram below.

NOTE: This is a NEW, GM OEM part.

NOTE: The GM parts manual incorrectly indicates this bolt as being 70mm long, whereas it should state 50mm instead.