So, I really like my Sierra Z71 and I think I'm going to be sticking with something similar in the future. It's a 2000 with 170,000 mi. So, the question I'm debating is how many mi can I expect my truck to run if I take good care of it, and how much $ is worth investing in it vs saving that money toward a newer one in the future? Also curious as to which upgrades might transfer to a newer, similar model, and what the smartest and most cost-effective add-ons would be. Any input would be appreciated!