I have an ol slant 6 that I got running yesterday. She's smoking like a chimney. Trying to figure out if I should swap the motor or nurse this one back to health. Lottsa blow buy coming out of the valve covers. Anything I should try before I ditch the motor for a v8? Diesel in the cylinders? Marvel oil? #6 is at 120 and the rest are between 130 and 140.