Have a 92 with ford motorsport 3 row rad. Boiled over last year in traffic. Gauge has never gone past second dash in 28 years. Changed out fan clutch last year seem to take care of the problem. This summer it is heating up again. the fan clutch has a little resistance when cold and hot. Shouldn't it be stiff while spinning while hot? Cools down at speed but gauge does move a aful alot when driving. I did just replace sending unit, I do trust the gauge. Pulled water pump last year also just to verify blades were in tact and pining with shaft. I noticed last nigh bubbles in the coolant when hot. Possible headgasket could my fan clutch be bad again?