0405htp Engine 14 Z

With the addition of a larger camshaft and larger valves, the MTI heads require larger valve springs to make sure everything is rocking and rolling like it should. The stock castings however do not have a large enough seat for the new springs, so MTI uses a 1.440-inch tool to widen it for the new spring cups. Without the new steel spring cups, the valve springs could tear up the soft aluminum.

MTI Stage III Heads Install - Tri-Power 427 -- Part II

With the addition of a larger camshaft and larger valves, the MTI heads require larger valve springs to make sure everything is rocking and rolling like it should. The stock castings however do not have a large enough seat for the new springs, so MTI uses a 1.440-inch tool to widen it for the new spring cups. Without the new steel spring cups, the valve springs could tear up the soft aluminum. View Related Article