Engine shut off while driving will not start

I did take the valve covers off, and they seem okay. Typical wiggle of lifters that you see in old engines too.

That's a good sign. Let me know what happens.

I'm almost there, got the stuff moved out of the way and the water pump off. There's a couple of studs on the water pump that also hold the timing cover in place. One stud just below the heater hose was extremely hard to get out, had to use an impact to retrieve it. When it came out, coolant poured out of the hole. Is that a sign of something?

It sounds normal, but to be sure can you please shoot a quick video with your phone so we can see what's going on, that would be great. You can upload it here with your response.

It's already out, but I circled the hole where it came out of here. Also, when I get the timing cover off, how do it line up the cam and crank? What am I looking for? And when laying the new chain on, what am I lining it up with?

Okay this is normal, some of the water pump bolts go through to the cooling system makes sure when you are reinstalling the bolt threads are clean and use silicone rubber to seal. Let me know what happens please.

Will the water pump/thermostat silicone by permatex work fine for that application?

Also your diagrams are for a V6 4.3L engine, mine is a V6 2.8L engine, if there is any difference.
So how do I now I have the cam and crank aligned? There's a #4 and also an offset dot on the cam sprocket. And a gold spot on the new chain.

Here's where I'm at: I see the white spots on the teeth. Is that indicative of jumped time? How else would I tell? And how to I line it up before installing the new gear?

I think I have it lined up. If you can line it up, doesn't that mean it didn't jump time? Also, there is something broken here. The tensioner?

So it's called a timing damper. Do you think the chain whiplashed and broke it? Would that cause the truck to shut off and not start? A lot of questions here.

It does look like the timing chain is loose which broke the guide. Here is how it is suppose to be lined up. Check this and get back to me please.

I have it lined up where the dot on the crank is in line with the raised mark on the cam, facing each other.

Is everything in line still? If so the timing chain did not jump, is this is the case the engine is worn out and needs replacement.

I feel like the cam should be moved slightly to the left. I guess we'll find out if it starts.

If it is off that will do it. Let me know what happens.

The crank sprocket isn't coming off. I've tried every gear puller you can buy, and even used a grinder to make the feet smaller to fit, they just slide off. The tool part number you have on the diagram leads to a $200.00 little puller, so I might just opt out on changing the crank sprocket.

Yep, they can be stuck on there pretty good. Let me know what happens.

I got it off using an OEM puller part #27011. And I put the new sprocket on by throwing it in my oven for 10 minutes at 250 degrees and it slid on like a glove and Is now on there for good.

Also, I had to turn the cam and the crank very slightly to the left. Not even a full tooth, is that significant? Only because they were not exactly lined up in the middle of the marks.

Not really, it sounds like normal wear I dont have much hope the timing chain the problem btw. I would look into a rebuilt engine.