It takes something significant to really make me upset. I had a headach to begin with this afternoon. It didn't help me any when I was just cruising back home in my '84 K5 at about 50mph when out of no where all of a sudden I hear and feel a grinding noise (like a handfull of bolts was dumped into the motor). The noise lasted at MOST 5 seconds, then there was a puff of smoke and that was it. I coasted to a stop. Checked the motor externally. Nothing out of the ordinary. Was running nice and cool, oil was fine, all fluids were fine. Nothing was leaking or dripping. Right after I heard the noise I wondered if the gear drive came apart or the cam broke or something; but timing cover was fine. I go to re-start it. Acts like it's froze. I turn it over by hand some. Then I try starting it again. Starter spins the motor over freely, but no fire. Spins over so freely it acts like there's no compression, and absolutely NO noise at all. No ticks, clicks or knocks. Then, notice oil coming out of a new hole in the oil pan that wasn't there a second before. Oil and coolant drain out. I havent taken it out yet or even looked at it more than the one spot in the pan next to the starter... but I can already tell that theres a hole in #8 cylinder. Goodbye 400 motor I was so proud of. It was the one motor I was completely done with and happy with. Now the '84 K5 joins the 20 others as a non-runner. I wouldn't have been so upset with the situation had there been warning, or had it simply been knocking. But there was NO warning and NO noise until it all went to crap in 5 seconds.