How much heat

[1972ho]

And pressure does it take to melt a sleeve like this without running nitrous.

[lefty o]

not much. once the head gasket is compromised , all the heat and pressure try's to cut its way through there.

[jed]

Could we see a picture of the head and the head gasket. They probably look like the sleeve.
As far as how much heat it takes to torch a sleve, compare it to a cutting torch. What is the temperature of the flame when you hit the oxygen leaver

[Roy]

I've seen several exhaust manifolds on HD trucks eat the manifold to head interface because of a broken bolt. Hot air under pressure has a tendency to erode things much like water jet cutting. I've seen your exact problem in a stock 3406E caterpillar. Melted clear through the 1/2" thick spacer plate cat uses to bring the deck surface up to the liner protrusions... plus torched the block, head, and those 2 liners where it blew. I forget what caused it to blow the gasket but they drove it like that for quite a few miles. Thinking broken head bolt.

[David Redszus]

And pressure does it take to melt a sleeve like this without running nitrous.

Combustion flame temperature is on the order of 4400F degs.

[Schurkey]

And pressure does it take to melt a sleeve like this without running nitrous.

I've got a near-stock 5.7L TBI small-block in a K1500 that looks a lot like your photo. Torched the head, too.

When the head gasket fails, that damage is just a matter of running-time.