Cadillac Repair: 97 Northstar head repair, bolt holes, shop mechanic

Question
Pressure test was done and a head job was required b/c engine overheats. After a month in the shop mechanic claims the engine is bad & unable to fix the problem!! Car starts up fine, just over heats. If heads sent to machine shop wouldn't it have been noticed if engine is severely damage beyond repair or if engine is bad would it still start? FYI: I myself replaced water pump, thermostat, radiator & check for collapsed hoses before reaching the shop. IS THE MECHANIC JERKING ME AROUND?? Please help!!

Answer
Sounds like he did not do the factory recommended procedures for checking the engine block surface for cracks and or warpage and just sent the heads out to be repaired and you do not know if the people who did the heads checked them according to factory specifications.

Since I do not know who forgot or did not know to do what it is hard to say who is to blame for this disaster.

After the engine was re-assembled did he add the sealant pellets to the engine to help seal the head gaskets ?.

His most likely error is that he did not drill out the head bolt holes according to factory directives and just re-used the original head bolts.