We own several gmc savana 3500 15 passenger vans. we seem to be having repeat issues with the exhaust manifold bolts braking and the manifolds cracking. our 2002 has been in 2-3 times and our 2005 has is now in for it's second manifold and bolts. the bolts are breaking and the manifolds are cracking. please encourage a recall for this type of vehicle. after checking the internet, we are not the only ones who are experiencing this problem with this gm motor. it looks as though this is a problem from all gmc vehicles with the vortec 6.0l motor. *tr