My method of choice for removing stuck bolts is to use an impact wrench. My logic here is that a jarring motion is more apt to shake it loose; whereas, a slow gradually increasing torque applied by hand will let it twist off and break. I'm not advocating to put the impact wrench on its maximum setting the first try. What I do is gradually increase the setting on the wrench so that somewhere along the way the bolt will shake loose. What is the better anti-seize compound to use on the manifolds? The silver stuff or the copper stuff? I generally use the silver stuff on aluminum and the copper on everything else. Is there any truth to this superstition or is the copper better in every application? Walt Tampa, FL