I'm in the process of replacing the waterpump and I've heard that after you get the new pump on and fill the radiator, after the car runs for a bit you'll have to add more coolant - is this true? Basically - in the end, whats the capacity? Thanks -

Yes, it's true. When you fill the radiator with coolant for the first time, the coolant will only fill up to the water pump and to the top of the thermostat. The vanes on the pump will not move since the engine is not running, and thus you will not be able to circulate the coolant throughout the system. Also, the thermostat is closed since it is below its rated temperature. Once the car is running, the coolant will start to circulate.

I do not know the volume offhand.

I use 1 gal of coolant to one of water and this about what it takes to fill her up . I wouldn't add the anti/freeze until after you have run the engine some because if you find a leak in a fitting or hose or what ever and you need to drain the coolant to remedy the problem then you either have a mess or loose the stuff. When you first start the engine watch the temp gage closely because you can trap air in the head and block and over heat the engine before the thermostat opens and allows the water to circulate. I prefer to start the engine and while she is at idle , keep feeling around the spark plug area and when the areas become hot, shut the engine off and let it set for 5 min or so. This will allow the heat that has been generated to cause the thermostat to open . Then start her up and be checking for leaks. If you don't find any , drain the radiator and pour in the the gallon of Coolant . You may want to have a richer mix being you are in Alaska. So a 50/50 mix may not do it for you . Gary