With a radiator overflow with its radiator inlet at the bottom is there a need to not fill the system and not leave room for expansion.

  Vic Correnti

You're correct, removing the thermostat doesn't reduce max operating temp, it will, however, increase warm up time which is not a particularly good thing. Coolant flow needs to be regulated so that the engine reaches optimum operating temperature quickly (thermostat closed), and then maintained within the optimum operating temperature range (thermostat opening and closing). Some of the flathead guys used to remove the thermostats and use fixed orifice restrictors instead. This may have worked OK for racing but I don't see it being beneficial for a street driven engine.

Before I plugged the bypass and drilled a 1/8” hole it took a lot longer to heat up. The 1/2” bypass hose let to much circulate I’m guessing. It also appeared let too much circulate after the thermostat was open causing over heating when in traffic.

Racers have been using restrictor washers for years…

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Another interesting subject (thermostats):

Years ago, when mine failed closed (VERY long ride home, stopping every few miles to let the motor cool), I investigated the new ‘fail open’ models.  None available for Y-Blocks then that were not designed to hold engine temp at modern higher levels (more efficient).

6 VOLTS/POS. GRD. NW INDIANA