Stuff Happens, replace or repair the parts and put it back together making sure you check clearances. Make sure the push rod guide plates are lined up properly.
Here is what happened to my AFR heads after who knows what happened. This was with a solid roller and pro Magnum rockers.
BTW the best engine builders of reliable sb engines are Nascar engine builders and sometimes they blow them up after 10 minutes.
Like I said first off stuff just happens.Internet trouble shooting rarely works.