buick ran without water...what damage?

If you run an iron block / aluminum head engine without water, will the heads warp or crack before the block is damaged? Would the heads warp before cracking? Would this all happen before the iron block got burnt up?

I just aquired a 1996 Buick centruy wagon for next to nothing. The Lady claims it had a leaking radiator and the car quit running while her son was driving and would not start again.

I have found that the radiator drain plug was broken out so it did indeed run out of water. The kid looks like a space cadet so no doubt to me that he kept on driving until it shut down.

3100 V-6 so it is an iron block with aluminum heads.

I fixed the leak and tried to start it up. It will not fire even though I have spark at the plugs and the engine spins freely.

The engine is leaking compression as I can hear and see either gas or water or both hissing out of the engine where the head and bolck mate. So I think either blown head gasket and/or warpped head at the least.

No way to check for water & oil mixing since there was no water and I can't check now since the car will not run.

I've interested in replacing / repairing the heads if this is possible. But only if there is any likelyhood the block has survived. A head swap is easier, faster and cheaper than a motor swap.

Do a compression test

new engine! If it ran out of water and got hot a quit its probably junk

The heads will certainly be damaged before the block. Remove the heads and take them to a machine shop to see if they are cracked or warped. If they are cracked replace them, if they are only mildly warped they may be able to be machined to the point where they can be used. If they are seriously warped then they will need replaced. Just remember to use new head bolts as they are torque to yield also be sure to change the oil before restarting.

That is pretty much my plan. I already planned on needing new heads. My biggest concern is that am I pretty much wasting my time trying to save this motor?

If the block is likely to be ok then I would feel better about trying a head swap.

I guess it costs me nothing to actually remove the heads and see what I see and then decide how much further to go.

Check your compression first. it might not be a head gasket.
I had an '86 2.8 V6 century overheat and the head gaskets were fine. But the gasket between the timing cover and the block was leaking coolant into the oil pan and the intake manifold gasket failed where coolant passage between the intake manifold and head were supposed to be sealed. After fixing those, The car ran fine -- lasted over 200,000 miles.
My current car, a 2000 Century also started leaking between the intake manifold and head and I also had to have the gasket replaced on that one.