I have a 1974 GTO that for some reason this year runs hot. I have replaced water pump, had heads checked and decked, radiator has been removed and cleaned , bypassed the heater core, new thermostat has been put in, and it still seems to heat up on the passenger side of motor, within 3 minutes of running heater hoses start jumping and bucking and are very hot to touch, at same time lower rad, hose is cold as with top hose. any ifo would be greatly welcomed