All, It's a K2500 Suburban with 7.4L vortec. It has 140k on it. There is a small coolant leak where the intake manifold meets the block. It is right where the oil fill tube goes in. I check overflow bottle and it was empty...took rad cap off and filled with the 50/50 dexcool quick fill stuff. Then added to the overflow until it was at cold full level. Talked to my brother-in-law and he said to put stop leak in it. He said there is a risk in pulling the intake manifold with that high of mileage as debris can fall into the engine and cause other problems. Is this a common source of leaks with the 454? Any other suggestions? It is my father-in-law that owns the truck....I think he has an exhaust leak as well. He has the typical ticking sound under load and when we started it with the hood open strong exhaust smell. Thanks in advance for the help.