For those of you not also participating on the "other" list; attached is
the flow data measured during my 20B dyno run with (full open) and
without the thermostat.  Considerably higher flow without.  Higher flow
= better cooling.  However; some means of controlling temp and speeding
the warmup is generally necessary.  Either control air flow, or, if you
have two radiators like I do, consider an in-line thermostat for one of
the rads.