wondering what would have caused this

[Starlight]

Had a customer that replaced his engine one time with a supposed reman from the lower main land of BC a couple years ago. He took it back for major engine repairs during his 1 year warranty period 4 times. He said the head gasket had failed all 4 times. It failed again 2 weeks after his ''warranty'' was over. Took it apart and saw right away why they had failed. The head bolt holes were full of debris and dirt and prevented full torque of the bolts. The dirt was compressed so tight on the bottom of the bolt it was almost like rock. Anyway, did a complete inframe with a new head and headbolts. The head gasket wasnt damaged as bad as this though. Not saying at all that this is the issue here but worth a check.