351C thermostat

I have a 351C 4V in my 73 Iso Fidia (Italian sedan). Engine is stock (except for Edelbrock intake & carb). It has a re-cored rad, new cap, high-flow180 stat (Milodon 16401), and I have just replaced the head gaskets. Cooling seems OK now, not like before when it would boil over after idling for even a few minutes (gasket problems, I'm pretty sure).
I am about to fit a Milodon high volume aluminum water pump as well, and my question is: should I still leave the restrictor plate with the small hole in it, in the thermostat housing, or remove it? What does this thing do??

Thanks guys,
Chris

Where is the restrictor? The thermostat should be in the housing.......

There is a metal plate below the thermostat with a small hole in the centre.
Chris

Is the restrictor in the bypass hose???? Guess I'm still not following you on where it is exactly....

Dave,

I guess what I am referring to is the "bypass orifice", a brass disc with a central hole, which on the Cleveland sits in the well below the thermostat on top of the front of the block. It has "Top" stamped on it.
I have just read (in the Hot Rod book covering the 351C & Boss 351 engines) that this part should never be removed, even if running no thermostat, as most of the coolant will then flow directly into the water pump rather than to the rad, causing overheating.
Sounds like I've answered my own question - unless anyone out there knows different...
Chris

That's correct, leave the restrictor in place....