CRACKED HEADS....WHERE TO BUY

[duddy]

Whats the point of replacing them? They usually crack from the exhaust valve to the glow plug hole, or from exhaust valve to exhaust valve, if they are really bad they will crack to an intake valve. They rarely go any further than that so whats the risk? Sure you might loose like 2psi of compression, big deal. Most people dont even know thier heads are cracked untill they pull the heads and find them. Do they gain any power by putting a set of new heads on? No. These heads have an induction hardened valve seat, meaning its part of the head, its not going to drop the seat out or anything like that so the risk is low. Hell i have even PUT hardened seats in an already cracked head with no issues, once the crack makes it to the glow plug hole or wherever they stop.
Ever heard of a crack going so far it pressurizes the cooling system on a 6.4? Me either

When I pulled the heads on mine, earlier this year, 5 out of the 8 cylinders were cracked but the head gaskets looked to be fine, I was pushing coolant excessicvely, but only when past 3/4 throttle. I am curious as to how installing new heads on mine fixed the problem, however I did install new head gaskets also. I put the problem at the cracks in the head, was I under the wrong assumption. All of the cracks were in the same location that you stated, valve to glow plug. Kinda wish I still had the heads to cut apart to look at. Just trying to learn, not trying to come off rude. I am guessing I may missed something on the gaskets.

 

[powerstroked08]

Your gasket was more than likely the culprit. And you fixed that with new gaskets. I could be wrong though.