440 problems ,new motor

I couldn't tell if the cam bearings were over heated , will have to get a better look . I know that i had good oiling . we did a preoil and had plenty oil out both sides of the rockers, but maybe not enough to run it ? I will check the bearing hole to see if it has any debris in it from the block bore and clean. I will have to also check see if the bearings hole is lined up even though it has pushed forward. Would like to know why the bolt broke and the cam siezed .Its a $800 repair plus time.Would not want to do it a second time.