My son just got a typical "little ol' lady" Nova he is bringing back to life ('78 6L 250 cc). This 27 year old car has only 83k miles and was driven only around town, 3 miles at a time, for all those years -- really. Anyway, the insides are pretty gunked up. He had removed the head and cleaned up as much as he can get to, but from the looks of the engine oil, only 500 miles after a change, there's no doubt what must still be in the engine and pan. I have heard that substituting a half qt. dexron for a half qt. oil at the next oil change is a good way to clean things up. Has anyone had the nerve to do this?? Something sounds wrong about that, but I cerainly would appreciate your comments. Thanks!