Geez guys, thanks for looking out for me. It would be a shame/waste to replace an engine that really didn't need to be replaced. I was (and still am) interested in hearing peoples' thoughts on what the best options are for replacement, but if we also want to dive deeper into the issue I am having, that is cool too. Do we need to look deeper into whether or not the smoke is a result of oil? It's going to be oil, fuel or coolant, right? The coolant level doesn't change. I think we can conclude that is not the issue. The smoking was happening prior to having the injection pump rebuilt, and prior to the injectors being replaced. Neither one of those impacted the smoking (which has been getting progressively worse for a number of years.) I get approximately 19 mpg. Can we conclude fuel is not the issue? The tail pipes are covered in oil, the van body around the pipes and aft get oily quickly. It smells like burning oil. When you run the engine with the air filter housing removed, looking directly into the intake manifold, there is a huge amount of smoke coming through the crankcase depression regulator (which I believe means that I have a lot of blow-by.) I add 1 or 2? quarts ever 1000 miles. The smoke has a light gray/blue color. Seems like burning oil to me, but if you think there is a chance that it might be something else, please let me know. If it is indeed oil, then, worn rings, ineffective valve stem seals, coked rings and/or cylinders, anything else? A few years ago I rigged up an "auxiliary fuel tank" (which was just a bottle that I plumbed into the fuel system) so that I could run seafoam and liquimoly through the system. I ran the products at full strength through the engine for 15 or 30 minutes each, mainly at idle, but reving up to approx 1200? RPM at the end of the runs for a minute or two. No change with smoking, idle smoothness, or anything at all. I did a compression test a year or two ago. The results in six cylinders were all about 370 psi and in two of them they were over 400 psi. I'm not a pro, but this didn't seem way too out of line to me. I spoke with a seasoned mechanic about the results and he said it was possible that the two cylinders could have been "wet" due to oil in the cylinders, leading to inaccurate psi readings. When I changed the injectors I remember that two of them were oily compared to the other six. I really wish that I would have notated which cylinders had the oily injectors...but I didn't. I'm not sure how to test the valve stem seals. I have realized that there is a possibility that these are causing the smoking, or contributing to it. The smoking has a very high correlation with load. If I pull a trailer, go up a hill, punch it, etc, the smoking increases. The higher the load, the heavier the smoke. If you watched the video you will see that it is seriously smoking while going up that hill! The engine has 262,000 miles. There was a sticker on the dash that said "MOHE 152,354" when I bought it. I'm nearly certain that someone has taken the engine out previously due to all the denting of the metal around the engine, and I am guessing that the sticker has to do with some type of engine work being done (overhaul, heads?) at 152,354 miles. Those are some of the things I can think of that might help in your hypotheses. Thank you!

And, at some point, please let me know what the best options are for replacement! It might be worth it to me. Thank you!