Slant 6 Coolant Flush

I took it to a radiator shop it's toast and leaking everywhere. It's been sitting outside for years.

I'm thinking about just putting the new one in and flushing it without the return hose on the radiator so that all the water just comes out when the water pump pushes it out. I took the thermostat out too.

Think that will work?

Yes, that will work. Just stick a garden hose into the top of your old radiator to keep water filling the system. Keep it running until the water comes out clean. That is exactly how I did my last flush.