u/Suitable-Kick-5898

First, I am not a mechanical wizard but can get by. My 1978 MGB needs a new lower hose on the radiator so I assume I will need to drain the radiator. All the videos I watch say to run the car to get the coolant flowing through the heater. Problem is my heater isn’t connected so do I still need to run the car before draining the fluid and replacing with new after installing a new hose? Thanks.