You cannot determine this until you remove the heads. Either way the heads must be removed and the gasket replaced. After removing the head you need to have it inspected by a machine shop.
To tell if the head is cracked, you have to remove it from the car, so you will replace the head gasket, anyway. Take the head to a machine shop and have it magnafluxed to see if it's cracked.
The head will need to be inspected at a machine shop. They can tell you if it is warped or cracked.
A blown gasket can be repaired by replacing the gasket...if you are talking about the head gasket, then you have to remove the cylinder head from the engine block and replace the gasket that is inbetween them. Cracked heads generally have to be replaced because they are made of aluminum which cannot be repaired permanently once it is cracked.
If you suspect the head and/or the block, have them "magnafuxed" by a machine shop. On the other hand, as you're pulling it apart, check the head gasket and if it's shot, there is usually only the one problem.
blown head gasket or cracked block blown head gasket or cracked block
Blown head gasket, cracked head or cracked block. Busted head gasket; cracked cylinder head; broken piston; or bad oil pan gasket if driving thru high water.
Could be head gasket, head, or cracked block
Blown head gasket or cracked head.
cracked head or blown head gasket
Head gasket Cracked head
you have a warped/or cracked head,or blown head gasket
Sounds like either head gasket, cracked head or cracked block