[v8volvo]

Sounds like it could all be symptoms of a tired motor, but could also be caused by a combination of relatively minor/peripheral factors that would be fairly easily resolved. It will pay to know 100% for sure where you stand before deciding on a rebuild or other comprehensive repair to what, for all we know right now, might be a perfectly healthy basic motor.

Black smoke could be fundamental mechanical problems, including low compression, but could also be excess fuel (as ngoma suggested), or, equally likely, engine not in proper timing or tune. Incorrect cam or pump timing can cause that (or failure to account for your high elevation when setting timing), or incorrect valve clearance, or inlet or exhaust restriction (including turbo issues), etc, etc, etc. Oil consumption could be tired motor, but could also be turbo problems, or other issues that you could track by diagnosis.

In short, I wouldn't jump the gun and assume you need an overhaul. That might ultimately be the case, but at this point you don't know for sure, and you certainly don't want to do that and then find out you didn't have to.

You said you had the IP rebuilt and the timing belts changed. Who did that work, and using what methods? What is the current timing setting? Why was the IP rebuilt? Why were the injectors rebuilt? What order was it all done in? Seconding ngoma's question, has compression been checked at any point, and if so, what were the results? What are the details about the oil consumption -- how much, under what conditions, what kind of oil in it, etc? Does it smoke only when you put your foot into it, or at other times as well, and what colors? How's the cold and warm starting? How's the power output? You'll want answers to every last one of these questions, and a handful others, before you'll have enough info to know what's currently going on and what the next steps need to be.

Welcome to the forum! You're in good company here, there are several Pinz owners, including forum member Hecklebone not too far from you in Denver CO, who has a 718 in similar spec to yours judging by the picture.