bent pushrods big block

i recently got my satellite running. 400 auto basically stock rebuild but with a crower .480 cam. i drove it twice and it was fine. i backed it in the garage and shut it off. the next morning i tried to start it. it just cranked and made a pinging noise. when it finally started it was real rough. so i did some checking. pulled the covers and discovered 3 bent intake pushrods. #s 3,4,5. it started fine in the garage every time. moved it around. actually drove it for 1/2 hour + twice, stopped and got gas, and it was perfect. and now this.. any ideas?