Bypass hose expanding

Intake gaskets have not been changed and it doesn't overheat. Pump is turning in the right direction. No bubbles in the coolant and no oil or coolant in the wrong area. I was thinking of drilling a small 1/8" hole in the thermostat flange to bypass coolant. I thought maybe the pump was a high volume. Doubt that would cause that. Thought about a restricted cooling system but then I would have more problems. I am gonna do a lk down test to find something. I try to live by don't fix it unless it's broke because I normally open up a can I can't close. Yet I can't turn a blind eye to this.