2000 Ford Mustang Water in cylinders

Intake manifold cracked and i changed the gaskets as i did not know it was cracked, and did an oil change at the same time. well the water leak was worse and i apparently left the old oring on when i put the new oring in. dumped out most of the oil from the filter area and my car wouldnt idle anymore. changed the filter and changed the intake manifold. started it and rough idle along with huge ammounts of white smoke (steam) pouring from the exhaust and radiator pressure cap. now people say its the head gaskets. upon me taking the heads off water is in both sides of the back 3 cylinders. would a blown head gasket cause water in both sides and that many cylinders???? Yes she ran with little water that day dont know if she was dry though. also ran with low oil. so what do you think. head gaskets, cracked head, cracked block?? whats my next move. thank you