Equalizer Head Cooling System rapidly Cools and Equalizes the heads and block for improved and equal engine cooling and longevity. The Equalizer Head Cooling system is designed to correct the poor coolant flow condition that exists in the 6.5 Hummer which is the cause of the majority of engine failures. Poor coolant flow through the block and heads causes extremely high operating temperatures in the rear portion of the block and central to rear portions of the cyl heads. These unequal temperatures create undue heat-stress conditions that lead to cracking cylinder walls. By creating proper coolant flow through the block and heads, the Equalizer system eliminates localized high temperature areas reducing heat-stress in these castings to help prevent cracking and breaking. Each system includes a patented perportioning valve which eaqualizes head pressure for even cooling and a new coolent crossover manifold for proper coolent flow. The Equalizer system is vital to a reliable long lasting engine.