I suggest you go ahead and replace just the water pump seal if that's all that's leaking...no pump required. Those "stop leaks" will plug all holes.... including ones in your radiator and heater core.

70 Roadrunner convt. street car 440+6, NOS, 4-spd, SS springs '96 Mustang GT convt. street car '04 4.6 SOHC, NOS, auto, lowered "Officer, that button is for short on-ramps"