I still think that Chevrolet didn't finish the job on exhaust manifolds. The guide pin is great for installing the exhaust manifold, but after everything is in place and snugged up, I think the guide pin should be removed and a bolt put in it's place to tighten the ends of the manifold. This may not be so much the case with a one piece manifold, but especially the case with a two piece set of headers.
