Its all about the maintenance. The core engine should have no trouble going 300k+ if you follow the rules. Im not even worried about the electronics on these trucks. The emissions scares me though. Already we have seen problems with the DPF. they are supposed to be good for 150,000 but I have a hard time seeing that happen. I had mine replaced with less than 3k on the clock. I have a hard time thinking it will make it to 150k now.
In the 70's people wouldnt order power windows because "its just something more to go wrong, anything electronic is going to break". How ridiculous does that sound now?
In the 80's when fuel injection got popular people said "any time a computer is involved its going to fail". Lets see a show of hands how many of you would go back to a carburetor on your daily driver.
Plastic degas/overflow bottles have been standard since at least the early 80's (I had a 79 mustang and a 82 LTD that both had plastic).