I agree.
If you don't get a used engine, or otherwise reasonable repair, and you look for another new GM truck, GM's 7 year, 100k mile Platinum Protection Plan can be had for $1,700 or less, even on the Denali 4x4. Just use the GM reward points, provided for free, and buy it through an internet based Chevy dealer, like Knapp Motors. Plus, if you wait and don't buy it until just before you hit 12k miles, essentially the whole vehicle is covered for 112k miles. GM Service contracts work that way. The new GM Protection Plans aren't sold by most GM dealers because they aren't as profitable as they used to be, but all GM dealers must honor it. I've also learned that it pays more than Ally's service contract, so the Service Managers eventually learn to like it.
GM also sells one that will cover 125k additional miles, for a total of 137k miles.
I've heard that the 5.3 typically lasts over 200k miles, but If you decide to buy something else, I wouldn't blame you.
Many years ago, an oil pump died on our Chrysler 360 V8 , so I understand.