With these trucks, I tend to side with the mechanic for the most part... (See exception below.)
Swapping stuff out, just because a part is old does not always work out for the better.
A lot of factory original parts that have gone 100k+ miles may have been produced at a time when quality was better. New parts aren't necessarily better parts.
If it works great, think twice about swapping a perfectly good original part for a possibly inferior after-market, new part.
The exception I would say, based on my personal mishaps, would be to consider definitely being proactive when it comes to wheel hub assemblies. If you have no idea how old they are or suspect the might even be originals, think about replacing the hub assemblies (with speed sensors). At higher mileages, the original hubs are probably not far from failure.
Most new hubs come with matched and tested ABS wheel speed sensors already installed. Don't cheap out. Get the best your budget can afford. Better quality hubs will probably last as long as you own your truck. Cheap hubs may get you by for a short while, but you may have to replace them a second time. Avoid that. Get good ones...
