I have a friend that has a 93 buick skylark custom with the 3.3 litre engine. overheats and it acts like a themostat. It is not, tried three different brands. Not the water pump either, water is flowing across the radiator. There is a 50 degree temp swing from upper hose to lower hose....water is flowing through the motor. Any ideas?
69 x-11..LS1, 420.88 horse to the tires,750 Holley Ultra DP, Torquer V2, darksides headers, PRC heads, 10.8:1 compression, forged bottom end, 5 speed. 2008 King Ranch F150 4x4.