https://www.spoperformanceparts.com/...html?CATID=995

 

I think thats just the bolt that blocks off the vacuum tube. (I stuck a bolt in the vacuum hose to the egr also just to see if that was what caused a problem that I was having.) just pull off the vacuum hose that goes to the EGR and stick a bolt in it that will fit snug into the plastic fitting, hope this helps

 

That bolt is for a carb manifold. Don't think it has anything to do with the LT1.