this happened to me once at the track so I removed the vc and found a longer bolt then ran it down through until it stuck down far enough to put a 3/8" coarse lock nut on it ,then ran the rest of season forgetting about it, took a long time trying to figure why the manifold bolt wouldn't come out after the season was over it just keep spinning ,so it never was a problem until disassembled . but this might not work on that hole.
