Is it a safe assumption that I blew a head gasket or cracked/warped a head?

Should I start out by ordering a set of gaskets and then look for cracks once I break it down to the heads?

 

NOPE, by your description you have a blown engine so regroup and give a lot more accurate information as to what happened, what you have checked and exactly what the engine sound/feels like when describing the compression.

 

I noticed the temp gauge right before I got home, it hit the red line right before I turned it off in the driveway. Having turned AC/radio/etc off and windows down I could hear a loud clicking like bad rocker arms/rods.

I left the truck off for 3 or 4 hours (checked fluids first) then started it back up and pulled it into the garage to start working on it. It ran perfectly fine, no noises, felt perfect.

Left it in the garage for another 3 or 4 hours before working on it (since it's fathers day). All of the water was boiled out of the engine so I filled it back up. again checked the oil for any water and it still looked fine. Cranked it, it started just fine and ran for about 5 seconds then died. Tried turning it over again and it sounded like it didn't have compression, like my old 350 when it jumped timing.

That's the whole story.

Prior to this I replaced the coils/wires/plugs/CKSP/fuse box plus the front differential and front drive shaft. The drivetrain fixes were last week, the spark related pieces were a few weeks ago.

 

Your timeline doesn't add up. All of the water doesn't "boil out" between checking fluids and pulling it in the garage, unless your garage is 7 or 8 miles away.

 

Water was all gone first time I checked it, didn't bother trying to fill it to run the truck for 30 seconds.

 

Ahhh...so checked doesn't mean you did anything about it. You see, this is the problem. If you don't describe things that you did in a way others can understand, we won't get anywhere.

Now, describe what "sounding like it has no compression" means to you. The only plausible outcome I can think of right now that would be "no compression" would be no compression on one or more cylinders, but not all of them. I'm not thinking timing, I'm thinking you melted the side of a piston. Even then, that's only a symptom of the overheating.

I'd suggest you do a compression test. A leakdown would be even better if you have the facilities. Then drain your oil and see just how much of your motor is in it. After that, a cooling system pressure test would be good. See if/which cylinders fill with coolant.

 

Your first mistake was to shut the engine off, while that hot, instead of turning on your heater and letting the truck idle back to normal temp.
If you think you have no compression in all cylinders, then you are screwed. As mentioned above, a compression test will confirm your beliefs, so do that and get back to us with all 8 numbers.

 

I can pickup a compression tester at the auto store, may have to order a leakdown kit.

I would describe the "no compression" sound while attempting to crank it as: turns over way too easy. Normally you can hear the rhythmic sound of each cylinder compressing and releasing while cranking, but there's no resistence now when I crank it. While I don't think it's the timing chain either, it does feel and sound very similar to jumped timing where your valves are open during the compression stroke. My engine current feels and sounds about half-way between normal and fully jumped timing chain.

That's about the best I can describe it DarylJ, will perform tests and reply back. Thanks for the assistance guys.

 

If all of that coolant got on your new crank sensor it is toast.
No fuel in any of the cylinders will also let the engine turn over faster than what would be considered normal.
If your compression comes back fine replace the crank sensor.

 

what????