Before you go and spend money on anything, do a quick check for base engine damage. With the trans in park and the ignition off, jumper the start solenoid on the passenger fender and see how it sounds cranking over. If you aren't comfortable jumpering the start solenoid, you can remove the IDM relay and use the key. It should crank evenly with no "flare-ups." If cranking isn't even, a compression test is warranted. It should sound more like the one in the first video, not like the one in the second. The trucks in the videos are both 6 liters, but the same principle applies.