I pulled it after it had 50,000 miles on it. The warranty was unlimited up to then. It dropped 2 valves and had a rering job at 20,000. It used a lot of oil, but did not smoke. Chevrolet said it was normal. It was January 1971 when I installed a worked 450 hp 327 Corvette engine. It went in a modefied stock car leading the race when it overheated. It was stored in a barn near Me, until the guy moved to Florida. Listed on E-bay as a disassembled L72 with My history. Went to Florida to identify it and bring it home to PA. I rebuilt it and used the stock pistons with no gap rings. It sounds great and should not use too much oil this time. My car has a lot of History. NICK L72