So, having a few health issues stemming from the truck's previous life of neglect. First off, got the brake booster fixed, and it's back on the road and running fine, finally...
Since I got it back on the road last fall, it's let out this whitish smoke at warm idle that goes away once I rev it up and put a load on it. Didn't do that before the fuel filter debacle, so after researching I decided that it was dirty injectors. After trying a few fuel additives that didn't do a thing, I pulled the fuel filter off (now that I know to lube the o-rings to prevent air leaks, I'm not scared anymore) and filled it with seafoam, let it run for a couple minutes, shut it off, let it soak, then ran the truck hard for a bit. Talk about a smoky truck! I'm certain it's never rolled coal like that in its life! But it did clear up the white smoke and it idles more smoothly and runs better and seems to get slightly better economy.
But it did reveal that it was also blowing blue smoke, which was hidden by the white smoke. I've determined that it's a cylinder with either a stuck ring (fingers crossed it's that) or a scuffed cylinder wall allowing a.) blow-by and b.) oil into the combustion chamber. There is a noticable pulse coming out the oil filler neck while it's running. Also, after nearly 2,000 miles on this oil change, it's a half quart low, which is new, the last change didn't use a drop of oil. I figure a couple changes of quality oil with a few cans of seafoam dislodged some sludge that was preventing any leaking.
Having followed this guy on youtube for a while now:
I decided I'd give restore a go. It may be snake oil, but if anything, it's cheaper than a teardown on a truck I'm trying to flip...
Here's hoping that a miracle-in-a-can works and that the motor has a stuck piston ring.