what the hell is that!
The Best V8 Stories One Small Block at Time
the head cover's half of the hole so there's no way the plug could back out, and if it was missing you'd be losing a lot more oil. just put new sealant on it if you're taking the heads off
looks to me like that would be the oil port to keep the rear of the intake/trans bellhousing/anything under it well lubricated. I beleive GM did this to cut down on rust in those areas.
Al 95 Z28 engine is ready to drop in.





