Yes. It reduces coolant flow. For overheating at parade speed, double check the fan for proper location in the shroud, properly working clutch fan, correct water pump pulley size, and accurate base timing. Thanks, Gary H. -----Original Message----- ... Anyways, wouldn't a lot of sludge packed >in the bottom of your water jacket cause overheating >problems?..........MO.....sw iowa ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.