"Ran Fine When I Pulled It", Yeah Right!

I had a stock 400 that ran just about perfectly around town. No miss, no unusual oil use, decent mileage and pick up.
Tore it down to do a build on it. Nearly every top ring was broken, and the cylinder walls had deep, uneven gouges all around the top and middle of the bores. Actually had to go .060 to clean it all up!