Two cracked heads! Help!
 

I have a 99 Supra Launch with the Indmar in it and both heads are cracked. Where can I find replacements? Either new, used or rebuilt. Thanks guys, this has really put a damper on my season. P.S. All the freeze plugs are still good.

Sounds like freeze damage? Better check the block thoroughly before spending money on heads.

What was the cause of the damage? I have never seen heads freeze and not the block. I have seen both heads crack from over heating or running extremely lean in a demolition derby though.

Anyhow, you should be able to go to almost any engine machine shop and get a set of reconditioned heads for about $250-400 complete. Just male sure they match each other in port and valve size and that a good valve job was done during the rebuild. You can get brand new, complete performance heads from GM Performance 25534421 for about $400 if you shop around, list is $529.99

Anyhow, if you are even remotely skilled, you should be able to do the heads in a weekend. You can even do it in the boat..

The 'freeze plugs' on the block are just plugs to fill the holes left from sand casting the block. They are not designed to protect it, or indicate freezing.
Are you sure it's the heads and not the head gaskets?
Sam's advice is good.

Yeah I pulled off the exhaust manifolds and it is the heads. One has a hole the size of a golf ball and the other one is cracked.

so the question begs, why did you leave water in your engine in freezing temps?

Jimmy, to answer your begging question. There was water in the motor because we ride all year regardless of temp. While most are sitting by the fire enjoying hot cocoa in January and reading the new edition of Alliance or Wakeboarding magazine, were out slaying an empty lake.

Pull your intake manifold off. The block is most likely to crack down in the valley. It'll crack there usually before the heads crack.

Been there, done that. It only set me back three weeks and a couple grand to replace the engine myself. Now I have more HP and a 7 year warranty.

Be sure to mark the distributor position before removing it.

Mark the rotor's position in the distributor too!

Just make sure the heads aren't the only thing damaged. If you get rebuilt or reconditioned heads, find out if they have been "decked" - when they shave a tad off the mounting surface to make sure its true. This will change your valve train geometry slightly. can be compensated for, you just gotta know going in. No big deal, slap new gaskets and heads on and finish it up. Shouldn't take too long.