If you run a mechanical pump and it is rpm-friendly, do not use a thermostat. With electric pumps, Jay's method is good with a constant flow rate. With a mechanical pump, a thermostat with those holes drilled will open and close sporadically, due to the extra flow holes. A quick trip from idle to 7000 rpm when the thermostat happens to be closed will put extreme pressure in the cooling system......enough to blow all of the knock-in plugs out. Seen this more than one time. Screw-ins won't blow, but it sure is a strain on all of the seal areas. The proper Moroso restrictor ring is a good method with a mechanical pump.
