Help me identify this bolt

[wilson234]

I'm almost finished with my 964 engine rebuild and I have an unusual bolt that I have left over. I recall removing it from one of the rear engine brace, but found no home for this bolt. It was removed somewhere during the engine tin painting and remaining bolt ons while finalizing the reassembly of the engine. It looks similar to the bolts that hold smaller diaper hose clamps, but larger diameter and interestingly has what appears to be a rounded end. Obviously the head is a flat head. It appears to be some set screw or something to ensure a gap is maintained. Any help would be appreciated. It's driving me crazy, I spent a good hour looking over the parts diagrams to see if I could figure it out.

[Flat6pac]

I've built several 964 engines and have never seen one like it.
Bruce