Follow the olm until it tells you to "Change Oil", use a oil quality oil, and the engine will outlast the chassis.
We have had excellent service in our 6.0 trucks. Knock on wood, they have almost maintenance free except for a water pump and normal maintenance. I bet I still have 40-50% brakes left at 248 k miles on my daily work truck. My shop neighbor has the same truck and had same good service/luck as well.
Service the transmission, assuming you have a 4l80e, as well around 5k, then every 50k(filter every 100k) and it will provide very long service as well. I always used Mobil 1 ATF but have switched to Maxlife Dex/Merc because of the Dex vi requirement.
I have also always run an over sized oil filter, though many feel not necessary, either a M1 206 or Purolator Pure One PL25288. The Purolators are about half as much.
Ive also run a K&N air filter since about 100 miles. Not for performance but I like the idea of a serviceable filter to cut maintenance costs.