[Vwdiesel] flushing cooling system without thermostat okay?

[Will Taygan]

The 1980 truck is coming back together.  I want to do multiple flushes to
get the oil out of the cooling system.  Can I run the truck without the
thermostat without breaking anything?  That is, will the water pump still
work without the thermostat?  I've got the kind where the thermostat comes
out of the housing on the bottom of the water pump (Its own housing, not
inside the pump part).  Of course, I'll put the thermostat back in when I'm
done with the flushes.

Thanks,

Will Taygan
Concrete, WA