[dsraven]

can you post an underhood pic of your set up that shows the hoses connected etc? curious how things are laid out under there, size of hoses, if there are sharp elbows etc.
doing the flow test would help give you an idea of flow capacity without the thermostat
normal to have no coolant flow through rad until thermostat opens
do you have a heater or are you running a bypass loop at the water pump end so there is coolant flow through the block when the thermostat is closed? this helps reduce hot spots around cylinder heads and steam production when the thermostat is closed.