1969 1/2-1981 Pontiac Buick and Olds "11 Bolt" Water Pump Divider Plate

Water Pump Divider Plate 1969 1/2 to 1977 Reducing the gap between the backing plate and the impeller Pontiac owners have reported that (1) heat cycling may result in a distortion the backing plate and (2) coolant degradation may corrode the backing plate necessitating replacement.  Some aftermarket plates may have a deeper dome and incremental cooling gains may be experienced by reducing the backing plate-to-impeller vane clearance. In closing the impeller-to-plate gap pressure is built, efficiency is achieved and more coolant will route to the thermostat and radiator which initiates the engine cooling process.  Please note that inadequate clearance that results in an impeller vane to backing plate interference will cause friction.  Owner modifications to the Pontiac part design are performed at the owner's discretion and FAILURE TO MAINTAIN ADEQUATE CLEARANCE WILL VOID WARRANTY. Make Model Year Block CID Liters BUICK CENTURY 80-79 V8 301 4.9L BUICK CENTURY 81-80 V8 265 4.3L