After three months, I reassembled my 351 car, now with ported heads. I have been plagued by cooling system problems for the last two days: water spewing all over the engine, leaks in hoses, running too warm. I have conquered the leaks one by one, and the car now runs warm, but not hot. However, there are bubbles in the radiator. A knowledgeable friend told me that such bubbles do not necessarily equate to a blown head gasket, but I have always assumed otherwise. I just made a test drive of 20 minutes duraton and the car lost no coolant. Opinions appreciated.