Spacer, Exhaust Manifold Bolt, for 90~95 ZR-1 LT5. Sold individually.  Does not includes push-on retainer ring.  See image below 

NOTE: This is a USED, GM OEM part. 

Confusing to many ZR-1 owners & mechanics, is the "missing" bolts for the exhaust manifolds.  The fact is, they aren't missing as they were deliberately not installed by GM.  The absence of bolts in the manifold hole apparently doesn't affect exhaust sealing as the only bolt changes were made during 6 years of production was the elimination of the "center stud" on the 90~92 models. Bolts were added to the manifold on both holes adjacent to the stud slot for the 93~95 models.

It is however, nice to know that ALL of the bolt holes in the manifold have corresponding drilled & tapped holes.  This is especially nice when aftermarket headers are installed. 

 1990~92 EXHAUST BOLT PLACEMENT SCHEMATIC