[Snakebit]

Has any one tried placing a freeze plug in the upper radiator hose, with a 5/8" hole in the middle to act as a restrictor? Summit sells water restrictor washers that have 5/8", 3/4" and 1" holes.

It may take a little longer for the engine to warm up and then there is the question of possible over heating in traffic vs cruising down the highway. A thermostat will open and close to regulate temperature vs a restrictor providing a constant flow.