1974 International Truck s I have a disel v8 9.0 ltr that ov

I have a question for you, along with some ideas. Why did you change the w/pump, and was the engine overheating before you changed it? Also, did you change the thermostat too? If not, pull it out and take out the center piece with the spring,then put it back in. Slowly, fill the system with water until you can see it, but don't overfill it. Start it up, and let it run, keeping an eye on the water level. as it goes down and you start to see the radiator core, slowly add more water. If this works, you had a stuck t-stat. You might also want to make sure that the fan is not on backwards, it can happen. Good luck, mickey-d.