Bought a pair of stock Gen 5 454's fresh water cooled out of a Say Ray.ran decent 330-340 HP.Guy pulled to clean up and do bilge pulled of and to repair 1 motor.His mechanic said it had a blown head gasket,trace's of antifreeze out tail pipe,non in oil.He removed them and a newer pair of injected motors came along and I bought the ones he pulled.I pulled the heads, gaskets look to be blown.all the cylinders between them but no sign's of antifreeze going into the cylinder on the gaskets.I know they do have
different gaskets for gen4 and 5.But these motors have never been apart.They do have factory fresh water cooled cast iron manifolds and factory SS risers that look like the cast iron one.I heard somewhere that they had a problem at that flange where the SS riser bolts to the cast iron center rise manifold.So do they have the wrong head gaskets and were leaking at the riser joint or risers were loose allowing the antifreeze to get int the exhaust?? Any thoughts.[ATTACH=CONFIG]540913[/ATTACH][ATTACH=CONFIG]540913[/ATTACH][ATTACH=CONFIG]540914[/ATTACH]

the head gaskets look like victor,s.gm used a crapload of them and my guess is they are the origionals.it looks like the engine may have overheated causing the gasket problem.i would check the block&heads for any signs of warping.i personally had a similar issue with one of my cruiser engines[traces of water in the cylinders].it was a cracked exhaust manifold.

But you think that gaskets looks correct,and you can see they are blown.I'm sending the heads out to get a valve job so I will get them checked.Will have to try and check the block myself.Thanks

What does the pistons look like ? Detonation overtime - overheating along with the rest of what Mike said above.

[ATTACH=CONFIG]540917[/ATTACH]Piston's look fine relatively clean not much carbon build up that may be from the antifreeze.Block around the heads looks like it never been hot and truthfully look as good as any motor that I have taken apart that wasn't blown that I have seen.This motor does not look like it had ever been run hot or out of time or lean' plugs are perfect looking.Like I said had just traces of antifreeze out the pipes.

They, look like exactly what the 575SCI head gaskets look like after a period of time of running on the lean side. I'm willing to bet the deck and the heads are not flat at this point.