I am having overheating issues with my 1938 Buick Century 455 streetrod. Overheat happens on the highway. I am thinking blocking off intake bypass will allow all coolant to pass thru radiator? Any issues With blocking bypass hose? Can I leave thermostat in? Should I drill small holes in thermostat or bypass plug? Trust me this is the last resort…..I have tried everything else except engine oil cooler!