I am wishing to discuss maintenance in regards to replacement of items such as throttle position sensor, etc.. Looking to avoid critical failure due to higher mileage vehicle. I guess what I'm saying is...is there a point where we should consider replacement of systems and parts prior to failure, based on anticipated life? ECM, TPS, injection pump, injectors, etc..

There is a difference between preventative maintenance and repairs. Some of these parts you list are on the repair side of the world. So far, most of which is on these trucks are the same on their maintenance scheduling and does not change through the life.A tps, vp44, injector, etc. are nothing that can really be "maintained". Injectors, maybe.. a periodic cleaning and testing, sure. But most of which are things that just have to be replaced when the time comes. As a service life is unpredictable given their are so many variables.

I've accumulated spares over the years and carry them in a small tool box when I venture far from home. I do a couple of four wheeling trips every year and where we go we can be without cellphone service for days at a time so theres no calling anyone if there's a problem. Mechanically my truck is in great condition and I have no doubts about taking it on a 1200+ mile road trip (done it many times) but everything has a lifespan and there simply is no way of knowing what it is when it comes to electrical components. In my case every sensor on my truck except my APPS is 15+ yrs old, so it's only a matter of time.

No spare parts here.I just do my monthly inspections of the vehicle looking for damage, leaks, etc. Nothing more. I don't change sensors unless failed or throwing a error code. ECM replacement is needed if clean power is kept to it and it should last a very long time. Like CajFlynn made over 1 million miles on his ECM before replacement. Injection pump (VP44) I don't bother with it either as long as the historic MPG and performance is still good no need to mess with it.

The only thing I have ever had magically fail was the water pump. I would take the belt off and spin it feeling the bearings for wear every 25,000. Replace if it feels crappy..