Learn a lesson on bad gas

Put a rebuilt head on my car after sitting for 15yrs. Of coarse drained the gas as best I could. Put about five gallons of fresh fuel in it. Poured some fuel down the carb and fired it up. Started it let it run a few times. took it around the block three times and heard a metal clanging sound and it sputter. I pulled the valve cover and had a bent push rod. And all the intake valves are sticking. One is really bad, the one that bent the valve. So after all my work of trying to get this thing going. I might try putting a new push rod in and disconnecting the fuel line and starting it with fresh gas. This sucks.