[chevy355ss]

I just finished rebuilding a sbc 350 which had a problem with extreme blow by coming out of the valve covers...tore engine down to find 4 pistons (#1,5,8,6) had cracked ring lands, rings, and #5 cam side skirt broke off. Engine was .03 over and I had originally put std rings so I gave the damage up to that...Finally get the rebuilt engine with .03 rings and pistons (hypers) and only about 40 miles later the same extreme blow by coming from valve covers....Have not had a chance to do any tests or tear into it to see what is causing it this time but I have a pretty good feeling its either the rings or pistons cracked again....I am completely stumped as to wy this is happening....Any suggestions??????????